Amt

American Tower Corporation Raymond James 2005 Institutional Investor Conference March 7, 2005

American Tower Corporation “Safe Harbor” Statement under the Private Securities Litigation Reform Act of 1995: This presentation contains forward-looking statements concerning our goals, beliefs, strategies, future operating results and underlying assumptions. Actual results may differ materially from those indicated by these forward-looking statements as a result of various important factors, including those described under the caption "Factors That May Affect Future Results" in our SEC Form 10-Q for the quarter ended September 30, 2004. We undertake no obligation to update the information contained in this presentation to reflect subsequently occurring events or circumstances. Definitions and reconciliations to GAAP measures are provided at the end of the presentation.

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Correction of Accounting Practice for Ground Leases Restated Financial Statements As previously disclosed, the Company is restating its previously issued consolidated financial statements to correct its accounting practices for ground leases. The Company undertook a review of its lease accounting practices and determined that it should change the periods used to calculate depreciation expense and straight-line rent expense relating to certain of its tower assets and underlying ground leases. The primary effect of this accounting correction will be to accelerate to earlier periods non-cash rent expense and depreciation expense with respect to certain of the Company’s tower sites, resulting in an increase in non-cash expenses compared to what has previously been reported. PLEASE NOTE THAT THE FINANCIAL INFORMATION CONTAINED IN THIS PRESENTATION DOES NOT REFLECT THE RESTATEMENT. The Company will amend the appropriate filings with the Securities and Exchange Commission to include restated financial statements for periods ending on or prior to September 30, 2004. Until such filings are made, the financial statements and the related independent auditors’ reports contained in the Company’s prior filings with the Securities and Exchange Commission should no longer be relied upon. 3

American Tower

Market Leader

We Are #1 in the United States 3Q04 Tower Revenue

75% 3Q04 Tower Segment Operating Profit

12,300+ Wireless Towers Ranking is based on number of towers and revenue.

73% 5

We Are #1 in Mexico 3Q04 Tower Revenue

14%

3Q04 Tower Segment Operating Profit

16%

1,600+ Wireless Towers 200+ Broadcast Towers Ranking is based on number of towers.

6

We Are #1 in Broadcast 3Q04 Tower Revenue

7%

3Q04 Tower Segment Operating Profit

7%

140+ U.S. Broadcast Towers Ranking is based on number of towers.

7

High Quality Tower Assets Domestic • Approximately 85% of US towers in Top 100 BTA and core corridors • Approximately 80% of core tower sites have no competing tower within 1/2 mile International • Towers concentrated in major markets: Mexico City, Monterrey, Guadalajara and Acapulco in Mexico & Sao Paulo, Rio de Janeiro and Curitiba in Brazil • No significant competitor in Mexico & Brazil 8

Our High Quality Towers Over 50% Were Built by Tower Operators Other US Carriers 4%

International Wireless Carriers 10%

AT&T Microwave 7%

Built by ATC 34%

Alltel 13%

Verizon 14%

Built by Other Tower Operators 18%

9

Diverse Tenant Mix % of 2004 YTD Tower Revenue by Tenant Type Paging Other 5% ALLTEL 6% 5% Broadcasters Cingular & AWE 7% 15% Regional, Voice & Data 8%

Big 6 & Affiliates 58%

Nextel 8% Sprint PCS 4%

International WSP 17%

T-Mobile 6% Affiliates 7%

Verizon 12% 10

Strategic Transition Complete Tower Division Drives Profitability Revenue

Operating Profit

2004E

2001 3%

3%

2001

1%

2004E

16%

21% 39% 40%

97%

Rental & Management

99%

81%

Other Services

Verestar

2001 reflects amount originally reported in the 2001 Form 10-K filed on April 1, 2002. Does not include reclassifications related to subsequent commitments to dispose of Verestar, MT S Components, Flash T echnologies, Kline, Galaxy and three office buildings reported as discontinued operations in our Form 10-K filed on March 12, 2004. 2004 reflects the reported midpoint of disclosed outlook in our Form 8-K filed on October 28, 2004.

11

American Tower Strong Business Model & Performance

Strong Business Model • Stable and Growing Revenue • Relatively Fixed Expense Structure • Significant Operating Leverage & Margin Expansion • Minimal Capex • Growing Free Cash Flow • Consistent Delevering 13

Growing Revenue – Stable Fixed Costs Rental & Management Segment $48 million increase

$200 $175

($ millions)

$150 $125 $100

$0 increase

$75 $50 $25 $0

1Q02 2Q02 3Q02 4Q02 1Q03 2Q03 3Q03 4Q03 1Q04 2Q04 3Q04 Revenue

P rior quarters adjusted for subsequent discontinued operations.

Expense 14

Current Lease Term Renewals • Over 50% of tower revenue is not up for renewal until 2010 and beyond % of Tower Revenue up for Renewal 60% 50% 40% 30% 20% 10% 0% 2005

2006

2007

2008

2009

2010+

15

Tower Margins Expanding Rapidly 69%

70%

67%

64% 61%

58%

58%

55% 1Q02

2Q02

3Q02 4Q02

1Q03

2Q03 3Q03

4Q03

1Q04 2Q04

3Q04

Tower Operating Profit Margin 16

Towers Delivering on Outlook Operating Profit Actual vs. Outlook $125

($ millions)

$100

$75

$50

$25

$0 1Q02

2Q02

3Q02

4Q02

Low Outlook

1Q03

2Q03

3Q03

High Outlook

4Q03

1Q04

2Q04

3Q04

Reported

Chart show s reported quarterly operating profit for the tower segment versus quarterly outlook established and publicly disclosed at the beginning of each year.

17

Consistent Adjusted EBITDA Growth $115.7

$120

($ millions)

$100

23

GR A %C

$80 $68.5 $60

$40 1Q02 2Q02 3Q02 4Q02 1Q03 2Q03 3Q03 4Q03 1Q04 2Q04 3Q04 18

Continued Control of CAPEX $90

$83

($ millions)

$75 $60 $48 $45 $30

$25

$25 $19

$15

$14

$13

$16

$11

$8

$10

$0 1Q02 2Q02 3Q02 4Q02 1Q03 2Q03 3Q03 4Q03 1Q04 2Q04 3Q04 Improvements/Augmentation

Discretionary 19

Predictable Free Cash Flow FCF Growth $50 $34

($ millions)

$25

$11

$19

$21

3Q03

4Q03

$40

$26

$3 $0 1Q02

2Q02

($25)

3Q02 ($8)

4Q02

1Q03 ($2)

2Q03

1Q04

2Q04

3Q04

($39)

($50)

($75) ($79) ($100)

H istorical quarters are adjusted for subsequent discontinued operations.

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Balance Sheet Strengthening Ongoing Delevering 14.0x 12.2x 12.0x

Do w n 10.0x

5 .5

T urn s

8.0x 6.7x 6.0x

TARGET LEVERAGE: 4.0x – 6.0x 4.0x 1Q02 2Q02 3Q02 4Q02 1Q03 2Q03 3Q03 4Q03 1Q04 2Q04 3Q04 Net Leverage Ratio Historical quarters are adjusted f or subsequent discontinued operations.

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Refinancing Objectives Objectives ♦

♦

Maintain and increase financial flexibility –

Leverage capacity

–

Liquidity

Reduce interest expense –

♦

Progress/Status

Repurchase and refinance high cost debt

Achieve target capital structure –

Leverage target with performance cushion 4.0x – 6.0x

–

Longer term maturity/Low cost debt

2005 Ongoing 22

Lowering Cost of Capital $55 mm in Interest Expense Savings Annualized Interest Expense ($millions) $295 $277 $275

$272 $263

$255 $236 $235 $222 $215

$195

$175 3/31/2004

6/30/2004

9/30/2004

12/31/04E

Run-Rate Estimate

*12/31/04E reflects the midpoint of our fourth quarter 2004 i nteres t expense outlook, as reported in our Form 8-K filed on October 28, 2004. Run-Rate estimate reflec ts the effect of all repurc has es/refinanci ngs as of Dec ember 31, 2004.

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Debt Security Repurchases/Refinancings

Total Refinanced/ Repurchased as of 12/31/04 Annualized Net Interest Expense Savings to Date

9.375% Sr Notes

12.25% Sr Sub Disc Notes*

$858.1 mm

$309.7 mm

Approximately $64 mm

Remaining Face Amount Outstanding

$141.9 mm

Additional Potential Annualized Interest Expense Savings**

Approximately $40-50 mm

$498.3 mm

*The C ompany has repurchased $309.7 mm of fac e amount ($179.4 mm accreted value) of its 12.25% Sr Sub Disc Notes si nce 1Q04. **Assumes that all remaining 9.375% Sr Notes and 12.25% Sr Sub Disc Notes are repurc has ed or redeemed with free cas h fl ow and funds available under the revol ver.

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Free Cash Flow Growth Operating Performance and Refinancing Drives Free Cash Flow

Growing Free Cash Flow

Interest Savings 2006 New Business Interest Savings

Recurring FCF

2005 New Business Interest Savings

Recurring FCF

2004 New Business 2003 New Business

2002

2003

Recurring FCF

2004E

2005E

2006E

Capex Savings

NOTE: Graph provided solely to illustrate incremental impact of certain events on free cash flow growth, and is not based on actual or projected results.

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American Tower Confidence in the Future

Wireless Industry Trends US Market • Increasing wireless traffic driven by increased subscribers and more minutes of use (MOUs) • Network quality essential to avoid high wireless customer churn • 3G network deployment gaining momentum Mexico • Wireless subscribers and market penetration expected to expand significantly through 2008 • Wireless competition increases the demand for higher quality of service and coverage 27

US Wireless Subscriber & MOU Growth Requires Additional Cell Sites Cell Site Growth

180

900

160

160

800

140

140

700

120

120

600

100

100

500

80

80

400

60

60

300

40

40

200

20

20

100

0

0

180

1997 1998 1999 2000 2001 2002 2003 Subscribers (millions) Cell Sites (thousands)

Source: CTIA Wireless Survey, December 2003.

Minutes of Use Growth (billions)

0 1997

1998

1999

2000 2001

2002

2003

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Mexico’s Wireless Market Poised for Strong Future Growth Wireless Subscriber Growth (mm)

Wireless Market Penetration 80%

70 60

’03-’08E: 30 mm net adds

60 50

58%

60%

40 40%

30

30

29%

20 10

20% 8%

8

0 1999

2001

2003

Subscribers Source: Wall Street Estimates & Reports

2005E

2007E

Net Adds

0% 1999

2001

2003

Historical

2005E

2007E

Estimate 29

2004 YTD Domestic New Business

% Total Towers

% 2003 New Biz Revenue

% 2004 YTD New Biz Revenue

Top 100 BTA

59%

58%

63%

Core Areas & Corridors

26%

28%

25%

Other

15%

14%

12%

Tower Diversity

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Impact of Wireless Carrier Consolidation • Expect multi-year network integration process • Potential adverse impact based on overlapping towers will probably not be material • Network engineering requirements are not reduced by combining carriers and the combined carriers would be motivated to accelerate growth • Combined, financially stronger carrier is more likely to deploy next generation 3G networks earlier 31

Merged Network Hurdles • Technical Hurdle • Capacity Requirements Hurdle • Cost Hurdle • Contractual Hurdle

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Merger Overlaps Tower Revenue Impact is Minimal Tower Overlap

Annual Revenue Overlap

% 2005E Tower Revenue

AT&T Wireless & Cingular

430 sites

$11.1 mm

1.5%

Sprint & Nextel

520 sites

$12.5 mm

1.7%

Verizon & Nextel

710 sites

$17.7 mm

2.4%

Verizon & Sprint

570 sites

$13.2 mm

1.8%

The % of 2005E tower revenue was calc ulated using $732.5 million, the midpoi nt of our full year 2005 rental & management seg ment revenue outlook, as reported in our F orm 8K filed on October 28, 2004.

33

Key Investment Considerations • Well-diversified, market leader with an established portfolio • Industry leading consistent operating performance • Stable and growing free cash flow, accelerated by continued deleveraging • Deep management team with experience through business cycles 34

American Tower

Thank You

Definitions (Reconciliations to measures under GAAP follow this slide) •

• • • • • •

Operating Profit: Segment revenue less segment operating expenses before: depreciation, amortization and accretion; corporate general, administrative and development expense; and impairments, net loss on sale of long-lived assets and restructuring expense. Rental and management segment includes interest income, TV Azteca, net. Operating Profit Margin: Segment operating profit (see above) divided by segment revenue. Adjusted EBITDA: Income (loss) from continuing operations before depreciation, amortization and accretion and impairments, net loss on sale of long-lived assets and restructuring expense, plus interest income, TV Azteca, net. CAPEX: Payments for purchase of property and equipment and construction activities. Free Cash Flow: Adjusted EBITDA less interest expense and payments for purchase of property and equipment and construction activities. Net Debt: Total long-term obligations, including current portion, less cash and cash equivalents. Net Leverage: Net Debt divided by last quarter annualized Adjusted EBITDA.

36

GAAP Reconciliations ($mm) Adjuste d EBITDA and Fre e Cash Flow The reconciliation of net loss to adjusted EBITDA and free cash flow is as follows:

Net loss

1Q02 2Q02 3Q02 4Q02 1Q03 2Q03 3Q03 4Q03 1Q04 2Q04 3Q04 $ (634.4) $ (101.2) $ (353.9) $ (52.4) $ (91.6) $ (107.7) $ (52.9) $ (51.2) $ (42.9) $ (60.5) $ (55.9) 562.6 15.8

Cumulative effect of change in accounting principle, net Loss (income) from discontinued operations, net Loss from continuing operations

$

Interest expense Interest income Income tax benefit Depreciation, amortization and accretion Impairments, net (gain) loss on sale of long-lived assets and restructuring expense Loss (gain) on retirement of long-term obligations Other expenses Adjusted EBITDA

$

Interest expense Payments for purchase of property and equipment and construction activities Free cash flow

$

33.2

206.0

3.7

11.4

27.5

15.2

6.9

0.3

0.6

(1.3)

(56.0) $

(68.0) $ (147.9) $ (48.7) $ (80.2) $

(80.2) $ (37.7) $ (44.3) $ (42.6) $

(59.9) $

(57.2)

63.8 (1.0) (22.3) 74.2

65.5 (0.8) (27.4) 79.4

62.7 (0.8) (3.2) 78.7

62.4 (0.9) (14.9) 80.5

71.7 (0.9) (19.3) 79.6

71.2 (1.9) (17.6) 79.6

68.9 (1.2) (13.6) 77.7

68.0 (1.2) (15.7) 76.5

69.2 (1.1) (10.5) 77.1

68.0 (1.1) (17.2) 81.9

65.7 (1.2) (29.1) 78.7

(0.9) 8.9 1.8

8.0

84.4

9.9

18.3

5.9

1.6

3.7 8.5 25.8

8.0 35.8 1.2

7.6 (3.2) 2.4

12.3 5.1 4.2

3.9 8.1 2.2

5.4 31.4 1.7

8.8 48.0 2.0

96.1 $ 100.9 $ 104.9

$ 106.4

68.5

$

75.0 $

79.8 $ 89.9 $ 88.9 $

$ 110.2 $ 115.7

(63.8)

(65.5)

(62.7)

(62.4)

(71.7)

(71.2)

(68.9)

(68.0)

(69.2)

(68.0)

(65.7)

(83.3)

(48.0)

(24.6)

(24.6)

(18.8)

(13.9)

(13.2)

(15.7)

(10.8)

(7.8)

(9.9)

(78.6) $

(38.5) $

34.4 $

40.1

(7.5) $

2.9 $

(1.6) $

11.0 $

18.8 $

21.1

$

26.4

$

37

GAAP Reconciliations ($mm, except ratios) Net Levera ge Ratio The calc ulation of net leverage ratio is as follows :

Adjus ted EBITDA

$

Multiplied by four (annualization)

1Q02 68.5 x4

Annualized adjusted EBITDA

$

Long-term obligations, including current portion

$ 3,431.4

Cash and c ash equivalents Restric ted cash and investments Net debt Divided by annualized adjusted EBITDA Net Leverage Ratio

$

274.0

(29.6) (47.5)

2Q02 75.0

$

x4 $

300.0

$ 3,448.0 (29.5) (47.5)

3Q02 79.8

$

x4 $

319.2

$ 3,448.4 (64.9) -

4Q02 89.9

$

x4 $

359.6

$ 3,448.5 (127.3) -

1Q03 88.9

$

x4 $

355.6

$ 3,585.9 (101.4) (217.2)

2Q03 3Q03 96.1 $ 100.9 x4

$

384.4 $

$ 3,354.3

$ 3,371.0

$ 3,383.5

$ 3,321.2

$ 3,267.3

274.0

300.0

319.2

359.6

355.6

384.4

11.2x

10.6x

9.2x

8.4x

12.2x

9.2x

x4 403.6

$ 3,516.8 $ 3,490.6 (107.6) (192.9)

$

(66.1) (283.7)

$ 3,216.3 $ 3,140.8 403.6 7.8x

4Q03 1Q04 104.9 $ 106.4 x4

$

419.6 $

$ 3,361.2 (105.5) (170.0)

x4 425.6 3,299.2 (98.7) (119.1)

$ 3,085.7 $ 3,081.4 419.6 7.4x

$

425.6 7.2x

2Q04 3Q04 110.2 $ 115.7 x4

$

440.8 $ 3,266.8 (197.9) -

x4 462.8 3,218.4 (126.8) -

$ 3,068.9 $ 3,091.5 440.8

462.8

7.0x

6.7x

38

This presentation contains "forward-looking statements" concerning our goals, beliefs, expectations, strategies, objectives, plans, future operating results and underlying assumptions, and other statements that are not necessarily based on historical facts. Actual results may differ materially from those indicated in our forward-looking statements as a result of various important factors, including: (1) a decrease in demand for tower space would materially and adversely affect our operating results; (2) our substantial leverage and debt service obligations may adversely affect our operating results; (3) restrictive covenants in our credit facility and indentures could adversely affect our business by limiting our flexibility; (4) our participation or inability to participate in tower industry consolidation could involve certain risks; (5) if our wireless service provider customers consolidate or merge with each other to a significant degree, our growth, our revenue and our ability to generate positive cash flows could be adversely affected; (6) due to the long-term expectations of revenue from tenant leases, the tower industry is sensitive to the creditworthiness of its tenants; (7) our foreign operations are subject to expropriation risk, governmental regulation, funds inaccessibility, and foreign exchange exposure; (8) a substantial portion of our revenues is derived from a small number of customers; (9) new technologies could make our tower antenna leasing services less desirable to potential tenants and result in decreasing revenues; (10) our business is subject to government regulations and changes in current or future laws or regulations could restrict our ability to operate our business as we currently do; and (11) the bankruptcy proceeding of our Verestar subsidiary exposes us to risks and uncertainties. For other important factors that may cause actual results to differ materially from those indicated in our forwardlooking statements, we refer you to the information under the caption entitled "Factors That May Affect Future Results" in our Form 10-Q for the quarter ended September 30, 2004, which we incorporate herein by reference. We undertake no obligation to update the information contained in this presentation to reflect subsequently occurring events or circumstances.

39