Filed by Forest Oil Corporation

Pursuant to Rule 425 under the Securities Act of 1933

Subject Company:  Mariner Energy, Inc.

File No. 333-129096

These materials are not a substitute for the registration statement that was filed with the Securities and Exchange Commission in connection with the transaction, or the proxy statement/prospectus-information statement to be mailed to stockholders. The registration statement has not yet been declared effective.  Investors are urged to read the proxy statement/prospectus-information statement which will contain important information, including detailed risk factors, when it becomes available. The proxy statement/prospectus-information statement and other documents that will be filed by Forest and Mariner with the Securities and Exchange Commission will be available free of charge at the SEC’s website, www.sec.gov, or by directing a request when such a filing is made to Forest Oil Corporation, 707 17^th Street, Suite 3600, Denver, CO 80202, Attention: Investor Relations; or by directing a request when such a filing is made to Mariner Energy, Inc., 2101 CityWest Blvd., Bldg. 4, Ste. 900, Houston, TX 77042-2831, Attention: Investor Relations.

Mariner, Forest and their respective directors, and executive officers may be considered participants in the solicitation of proxies in connection with the proposed transaction. Information about the participants in the solicitation will be set forth in the proxy statement/prospectus-information statement when it becomes available.

1

Searchable text section of graphics shown above

[GRAPHIC]

THE “NEW” FST

Same Leadership. Same Strategies. Same Discipline. Improved Focus.

[LOGO] GROWTH PROGRESS MOMENTUM

UBS Denver Investor Tour

November 29, 2005

THE “NEW” FST – Operations Spin-Off Drives Value

•Innovative transaction provides new optionality and returns value directly to Forest’s shareholders

•Opportunistic tax-free spin / merge of offshore Gulf operations creates two highly focused and valuable enterprises

•Investment in Mariner Energy creates high quality, well positioned GOM independent with excellent track record and growth outlook

•Remaining Forest creates highly-focused onshore resource company to execute a more focused “acquire and exploit” strategy

•Forest’s portfolio of long-life, concentrated assets in high quality basins provides a foundation for sustainable organic growth

STREAMLINED ASSET BASE, IMPROVED FOCUS AND BETTER POSITIONED FOR GROWTH

[LOGO]

2

KEY TRANSACTION TERMS

Asset Contribution

•344 Bcfe of Forest offshore proved reserves (12/31/04)

Liability Contribution

•$200 Million of debt

•$50 Million of derivatives at 6/30/2005

•$157 Million of ARO

Structure

•Tax-free Reverse Morris Trust transaction

•Spin-off of offshore Gulf of Mexico operations

•Stock-for-stock merger of “SpinCo” and Mariner

Mariner Equity Ownership

•58.2% Forest shareholders

•41.8% Mariner shareholders

Mariner Management & Governance

•Scott D. Josey, Chairman & CEO

•7 member board

•2 members to be mutually agreed by Forest and Mariner

Expected Close

•Q1 2006 (economic effective date of July 1, 2005)*

•Forest and Mariner shareholders will each own freely tradable registered stock in Mariner upon closing

*  Subject to Mariner shareholder vote and SEC registration requirements and Forest bondholder consent

3

Combination [LOGO]

Mariner Contribution[LOGO]

•Management

•Deepwater, shelf, West Texas assets

•Exploration track record

•Prospect inventory

Forest Contribution[LOGO]

•Development expertise/personnel

•Underexploited shelf assets

•Identified exploitation opportunities

•Cash flow

42% Equity ownership [GRAPHIC] 58% Equity ownership

•Dynamic GOM player with scale and expertise to effectively compete in the shelf, deep shelf, and deepwater

•Strong cash flow

•Modest debt level

•Shareholders benefit from the diversity and upside potential intrinsic in these complementary asset bases

•Blend of exploration and exploitation opportunities

Mariner – SpinCo Trend Map

[GRAPHIC]

Shelf and Deepwater (470,000+ net undeveloped acres)

•Creates a leading Gulf of Mexico focused independent

•Balances deepwater exploration with low risk shelf production

•Adds high impact deep shelf and ultra-deep shelf opportunities

•Extensive prospects in inventory

•Synergies achieved through property overlap and operating efficiencies

Combined Reserves as of 12/31/04 615 Bcfe*

[CHART]

*Reserves are pro-forma acquisition of Bass Lite

GOM Lease Expirations 2004-2005: 563 Leases

[GRAPHIC]

GOM Lease Expirations 2006-07: 2,411 Leases

[GRAPHIC]

GOM Lease Expirations

[GRAPHIC]

Mariner Organization

Chairman
CEO
Scott Josey
(25 years)
			COO
			Dalton Polasek
			(30 years)
VP	VP	VP	VP	VP	VP
General Counsel	Corporate Development	CFO	CXO	Shelf & Onshore	Deepwater
Teresa Bushman	Jesus Melendrez	Rick Lester	Mike van den Bold	Judd Hansen	Cory Loegering
(20 years)	(25 years)	(31 years)	(19 years)	(27 years)	(28 years)

Exploration Track Record

[GRAPHIC]

Significant Discoveries….over 80% Internally Generated

Deepwater Operations Expertise

[GRAPHIC]

Historical Performance

Proved Reserves

[CHART]

*Reserves are pro-forma acquisition of Bass Lite

Daily Production

[CHART]

EBITDA

[CHART]

*Includes $10MM for non-cash stock compensation

Reserves Replacement Rate

[CHART]

Rolling 3-Year F&D Costs

[CHART]

*Excludes future development capital of $255MM

CAPEX

[CHART]

Strong Competitive Positioning and Value

2004 Proved Reserves	2005 Production
[CHART]	[CHART]
2005 EV/Proved Reserves	2005 EV/Production
[CHART]	[CHART]

*Reserves are pro-forma for acquisition of Bass Lite

Note: Enterprise values as of November 22, 2005

FOREST OIL’S REMAINING ASSETS

[GRAPHIC]

Alaska
12/31/04 Reserves (Bcfe)	117
YTD 2005 Production (MMcfe/d)	41
12/31/04 Net Acreage (M)	1,182
Reserve Life	7.9
Canada
12/31/04 Reserves (Bcfe)	152
YTD 2005 Production (MMcfe/d)	71
12/31/04 Net Acreage (M)	930
Reserve Life	5.9
Western
12/31/04 Reserves (Bcfe)*	643
YTD 2005 Production (MMcfe/d)	112
12/31/04 Net Acreage (M)*	254
Reserve Life*	15.8
Southern
12/31/04 Reserves (Bcfe)*	198
YTD 2005 Production (MMcfe/d)	45
12/31/04 Net Acreage (M)*	147
Reserve Life	12.1
Consolidated
12/31/04 Reserves (Bcfe)*	1,110
YTD 2005 Production (MMcfe/d)	269
12/31/04 Net Acreage (M)*	7,698
Reserve Life	11.3

* Pro Forma for the Buffalo Wallow Acquisition and offshore spin-off

[LOGO]

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REALIGNING ASSET BASE – “The Perfect Pie”

Old Forest Oil	New Forest Oil
[CHART]	[CHART]
2004 Reserves: 1,454 Bcfe * 61% Gas 75% PD	2004 Reserves: 1,110 Bcfe * 55% Gas 74% PD
[CHART]	[CHART]
YTD 2005 Production: 475 MMcfe/d 2005 R/P: 8.0	YTD 2005 Production: 269 MMcfe/d 2005 R/P: 11.3

*  Pro-Forma for the Buffalo Wallow acquisition and offshore spin-off

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…FOCUSED STRATEGY…

“4 Point” Philosophy

1.Leadership

•Superb technical talent pool

•Deep managerial bench

•Proven acquiror

2.Strategies

•Sustainable growth at high returns

•Intense focus on costs

3.Discipline

•Rigorous evaluation criteria

•Capital budget adherence

4.Focus

•Focused onshore portfolio

•Critical mass in core areas

Revised “4 Point” Strategy

1.Grow organically

•12% prod. growth in 2006 (10% organic)

•Exploit “new” portfolio and resource plays

2.Identify attractive acquisition opportunities

•Strong track record and momentum

•Target prospect rich opportunities supported by land

•Tax-efficient acquiror ($706 MM NOLs)

3.Reduce costs

•Cost control in all areas

4.Preserve financial flexibility

•Strong free cash flow profile

•Remain in targeted Net Debt / Book Cap range of 30% - 40%

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…AND COMPELLING INVESTOR APPEAL

•Uniquely positioned mid-cap with critical mass in multiple high quality basins

•Extensive drilling inventory in Texas Panhandle / Mid-Continent area

•Large scale Permian footprint and Haley Atoka exposure

•High quality Alberta Plains and Canadian Foothills inventory

•Significant Rockies acreage position

•High impact Onshore Louisiana and Texas exploration

•Significant acreage in developing Alaska gas

•Well-balanced resource play with visible organic growth profile

•Extensive exploitation inventory; over 2,350 projects

•Attractive exploration upside; 7.1 million net undeveloped acres

•Successful acquisition and exploitation track record fueling steady replenishment of drilling opportunities

•In excess of $1 billion in strategic acquisitions over last 2 years adding 681 Bcfe at an all-in cost of $1.51 / Mcfe

•Demonstrated ability to be disciplined with capital spending

•Excellent tax loss carryforward position (US $466 MM and Canada $240 MM)

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SUSTAINABLE GROWTH PROFILE

[CHART]

* Adjusted for 7 MMcfe/d announced deferrals due to Hurricanes

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EXTENSIVE PROSPECT INVENTORY

	Project	Net Reserve
Key Growth Platforms	Inventory	Potential (Bcfe)
Buffalo Wallow (Texas Panhandle)	346	377
• From 40 to 20-acre spacing
Permian Basin	679	565
• 30,000 net acres in Haley Atoka
Wild River	120	54
• From 640 to 160 acre spacing
Southern	419	513
• Frio, Yegua, Wilcox, Vicksburg trend
Onshore Cook Inlet Gas	35	1,875
Total	1,599	3,384

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[GRAPHIC]

WESTERN BUSINESS UNIT

[LOGO] GROWTH PROGRESS MOMENTUM

WESTERN BUSINESS UNIT

[GRAPHIC]

Existing Portfolio / Highlights

•Panhandle – Buffalo Wallow

•Permian Basin - Vermejo, Haley, Apollo, Fullerton, Tex-Mex, Martin

•Washakie & Green River Basins – Wyoming

•Williston Basin

•Anadarko Basin

•San Juan Basin

Resource Upside

•Panhandle development drilling

•Waterfloods, downspacing and development drilling in Permian

•Excellent undeveloped acreage position in Rockies, Greater Haley Area and Panhandle

•Downspacing in Rockies, San Juan and Oklahoma

Other Assets

•Gas plants at Whitney Canyon, Anschutz Ranch and Altamont Bluebell

[LOGO]

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WESTERN BUSINESS UNIT - Buffalo Wallow

•Very active resource play in Texas Panhandle focused Granite Wash interval

•Multiple zones commingled utilizing “slick water” frac technology

•Offset operators already downspacing to 20 acres

•Deep potential in Atoka and Morrow

•Active operators include Chesapeake, Patina/Noble, Samson and Newfield

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[GRAPHIC]

•120 Bcfe of estimated proved reserves and production of 32 MMcfe/d

•370 drillsites identified (40 identified as PUD)

•Field approved for 20 acre downspacing

•Production increased 60% since acquisition (100% success rate)

•Production expected to increase to 40 to 45 MMcfe/d in 2006

•33,000+ gross acres in trend

•Deep pay found in the Atoka

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BUFFALO WALLOW – Typical Well Type Curve

[CHART]

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BUFFALO WALLOW – 20 Acre Spacing

Buffalo Wallow Drainage Area Histogram

89 of 100 wells drain < 20 acres

[CHART]

•TRRC approves 20-acre spacing Nov 2004

•Wells drain less than 20-acres

•No interference to date in 20-acre wells

Patina Oil & Gas Corporation

Docket No. 10-0238004

Date:  October 8, 2004

EXHIBIT

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BUFFALO WALLOW – Panhandle Area

	Producing Wells			Future Locations			Total
Field	40-acre	20-acre	Total	40-acre	20-acre	Total	40-acre	20-acre	Total
Buffalo Wallow (13 sections)	64	6	70	144	202	346	208	208	416

	Producing Wells			Future Locations			Total
Field	160-acre	80-acre	Total	160-acre	80-acre	Total	160-acre	80-acre	Total
Frye (3 sections	6	0	6	6	12	18	12	12	24
Austin (5.75 sections)	1	0	1	22	23	45	23	23	46
Other (3 sections)	0	0	0	12	12	24	12	12	24
Total	7	0	7	40	47	87	47	47	94

A SIGNIFICANT INVENTORY OF LOCATIONS AND DOWNSPACING OPPORTUNITIES

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WESTERN BUSINESS UNIT – Permian Basin

[GRAPHIC]

•Very active area for FST; tripled in size

•Vermejo / Slash Ranch / Dimmit / Apollo

•Deep Atoka / Morrow and Fusselman potential

•High industry activity area

•Active shallow Delaware recompletion program

•Central Midland Basin

•Tex-Mex

•New waterfloods

•High exploitation activity

•Step-out drilling successful at Tex-Mex

•Martin

•Development drilling

•Multiple pay intervals with recompletion opportunities

•Forest owned drilling rigs operating in the basin

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WESTERN BUSINESS UNIT – Greater Haley Deep Gas Play

[GRAPHIC]

Greater Haley Area

•Rejuvenated by Anadarko in 2003

•Forest is actively leasing in the play; currently 30,000 net acres

Slash Ranch/Demmit

•Fusselman/Atoka/Morrow stacked pay potential

•Bell Canyon and Cherry Canyon Recompletion program

Apollo

•Active recompletion and re-entry program

Vermejo Field

•Active 2 rig drilling program

•Active recompletion and re-entry program

•Atoka sidetrack opportunities may exist

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WESTERN BUSINESS UNIT – Tex Mex

[GRAPHIC]

•San Andres, Clearfork, Wichita Albany multipay field

•Pilot Clearfork – Wichita Albany Waterflood Project installed November 2003

•Active 2 rig drilling program (Forest owned rigs)

•Active acreage acquisition program

•Multiple wells have bypassed pay recompletion opportunities

•20 acre infill potential

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WESTERN BUSINESS UNIT – Martin

•Increased production 50% since acquisition

•Shallow San Andres and Clearfork objectives

•IP range from 84 BOEPD to 263 BOEPD

•Offset operators have applied for 10 acre downspacing

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[GRAPHIC]

CANADIAN BUSINESS UNIT

[LOGO] GROWTH PROGRESS MOMEMTUM

CANADIAN BUSINESS UNIT – Overview

[GRAPHIC]

Existing Portfolio / Highlights/ Resource Upside

•Wild River exploration (deep) and development (downspacing)

•Foothills exploration at Palliser, Copton, Narraway, Ojay and Waterton

•Evi: Slave Point Oil – Resource Play

Existing Portfolio / Highlights/ Resource Upside (cont.)

•Large acreage position in Plains and Foothills

•Beaufort Sea / MacKenzie Delta unbooked discoveries of 242 Bcfe

•Drilled 22 discoveries in MacKenzie Delta with Gulf Canada (Conoco)

Other Assets

•930,000 net acres (89% undeveloped)

•Plant and pipeline infrastructure

•Marketing joint venture with Cinergy

•Tax pools

[LOGO]

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CANADIAN BUSINESS UNIT – Wild River

[GRAPHIC]

•Very active area for shallow and deep gas exploration on 21,000 acres

•Gross production increased from 17 to 49 MMcfe/d

•Well costs reduced

•Four wells awaiting pipeline connection

•Two drilling rigs in the field

•160 acre down-spacing and commingling recently approved

•Over 100 down-spacing locations identified

33

CANADIAN BUSINESS UNIT – Palliser Block

[GRAPHIC]

•Five major Cretaceous structures have been identified on CFOL lands

•Up to 15 potential drill locations for Cretaceous are available

•Two Paleozoic structures with 4 drill locations are possible

•Working interest:  50 –57%

•25,000 gross acres

•Deep sour gas potential

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CANADIAN BUSINESS UNIT – Narraway Block

[GRAPHIC]

•Three major Cretaceous structures have been identified on CFOL lands

•A further 8 potential drilling locations for Cretaceous are available

•One Paleozoic structure with two drill locations are possible

•Working interest:  50 –100%

•20,000 gross acres

•Deep sour gas potential

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CANADIAN BUSINESS UNIT – Evi Slave Point Project

[GRAPHIC]

•2005 drilling

•2 vertical wells

•1 horizontal

•2006 drilling

•11 vertical wells

•41 potential development locations

•Reserve potential

•50,000 to > 100,000 Bbls/well

•Initial production rate

•45 –75 Bopd/well

•Working interest:  25 –100%

•9,000 gross acres

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[GRAPHIC]

SOUTHERN BUSINESS UNIT

[LOGO] GROWTH PROGRESS MOMEMTUM

SOUTHERN BUSINESS UNIT

[GRAPHIC]

•Acquired 3-D seismic at Bonus, Katy, Liberty & Sabine

•Large contiguous 3-D seismic coverage from West White Lake to Sweet Lake

•Net undeveloped acreage increased from 3,000 to 110,000 acres

•Took over drilling operations at Katy with infill opportunities

•Took over operations at Mercy

[LOGO]

38

SOUTHERN BUSINESS UNIT - Sabine

[GRAPHIC]

•Approximately 157,000 acres leased or optioned in this prolific Yegua and Wilcox trend (45% WI)

•260 square miles of 3-D and 2,000 linear miles of 2-D data available to map

•Five wells in the field completed at an average of 3.7 MMcfe/d

•One well completing

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SOUTHERN BUSINESS UNIT – Sabine Seismic

[GRAPHIC]

“Hurricane Creek” Proposed 3 – D

•North of current Forest drilling activity

•Forest and partners control approximately 50% of acreage to be shot

•Multiple Cockfield and Wilcox leads based on 2 –D subsurface

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SOUTHERN BUSINESS UNIT – Katy

Katy Field

•Took over drilling operations

•Drilled 2 Frio discoveries in 2005

•Combined IP’s < 1 MMcf/d for total investment of $585M

•Sparks recompletion tested at 2 MMcfe/d

•Virgin pressure discovered on Wilcox recompletion

•Yegua has produced 6 Tcf from this field

•122 square miles of 3D seismic coverage

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SOUTHERN BUSINESS UNIT – Cameron Parish

SEI Cameron Prairie 3D; 462 sq. mi. 3-D for Field Evaluation and Exploration

[GRAPHIC]

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[GRAPHIC]

ALASKA BUSINESS UNIT

[LOGO] GROWTH PROGRESS MOMEMTUM

ALASKA BUSINESS UNIT - Overview

[GRAPHIC]

Existing Portfolio / Highlights

•Gas fields – W. Foreland & Three Mile Creek

•Oil fields – Redoubt Shoal, Trading Bay, West McArthur River & Prudhoe Bay

Resource Upside

•Onshore exploratory gas prospects

•Offshore exploratory oil prospects

•Higher waterflood recovery

Other Assets

•Cook Inlet Pipeline and Drift River Oil Terminal

•46.8% ownership in 6 platform rigs

•Kustatan onshore facility

•1,182,000 net acres (97% undeveloped)

[LOGO]

44

ALASKA BUSINESS UNIT - Onshore Alaska Gas

[GRAPHIC]

•Undeveloped onshore net acreage in excess of 1,100,000 acres

•West Foreland #2 (100% WI) tested 15 MMcfe/d

•Three Mile Creek Unit #1 (30% WI) tested 5 MMcfe/d from shallow zone

•Net undeveloped acreage of approximately 106,000 acres surrounding the three discoveries (recently added 18,000 acres)

•New supply contract commences in Q4 2005

•2 additional tests planned in 2005

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[GRAPHIC]

INTERNATIONAL BUSINESS UNIT

[LOGO] GROWTH PROGRESS MOMEMTUM

INTERNATIONAL BUSINESS UNIT

[GRAPHIC]

	12/31/04 Total
International	Acreage (Net)
South Africa	2,927,066
Gabon	963,710
Italy	756,857

Existing Portfolio / Highlights

•South Africa gas tested over 220 MMcfe/d from 5 wells

•Gabon offshore oil block with full carry on costs

•Italy shallow gas – Po Valley and Bomba

Resource Upside

•Undeveloped acreage portion with large blocks

•Unbooked reserves in South Africa, Italy and Australia

•South Africa deep water play

Future Strategy

•High grade to three best areas

•Explore using promoted or carried working interest

•Potential monetization or trade opportunities

[LOGO]

47

[GRAPHIC]

ACQUISITIONS/HEDGING

[LOGO] GROWTH PROGRESS MOMEMTUM

TARGETED ACQUISITION PROGRAM

	Purchase	Initial		$ Amount Per	Net	Undevel.	Other	Amount Per
Acquisition	Price	Production	Reserves	Mcfe / Res.	Acreage	Acreage	Assets	Mcfe / Res.
	($MM)	(MMcfe/d)	(Bcfe)
Unocal	224.0	66	138	1.62	252,000	93,000	15.9	1.51
New Permian	112.9	25	109	1.04	32,000	5,000	—	1.04
Wiser Oil	330.0	64	191	1.73	388,000	288,000	57.6	1.43
Buffalo Wallow	235.0	25	120	1.96	22,000	11,000	2.2	1.94
Others	129.1	27	123	1.05	100,000	45,000	19.3	.89
Total	1,031.0	207	681	1.51	794,000	442,000	95.0	1.37

•Total F&D cost of $1.51 on 681 Bcfe of reserves w/o allocation, $1.37 w/ allocation

•Production per Mcfe/d acquired at $4,981 with R/P of 9 years

•Primarily proved developed reserves, FST retained upside

[LOGO]

49

ACQUISITION LOOKBACK SUMMARY – 6/30/2005

Unocal, New Permian, Wiser, S. Bonus, Minihan, McAllen & Oxy

	Investment		Reserves		$ / Mcfe
	($MM)		(Bcfe)
Original Acquisition	775		517		1.50
Cash Flow / Production	(346	)	(91	)	3.80
Subtotal	429		426		1.01
Capital Projects	188		133		1.41
Total Investment	617		559		1.10

•45% of original investment paid out with 82% of reserves remaining

•36% of total investment paid out with 108% of reserves remaining

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RISK MANAGEMENT – Favorably Positioned

	2006
	Pre-Spin				Spin		Post-Spin
Natural Gas Swaps
Contract Volumes (BBtu/d)	50.0				40.0		10.0
Weighted Average Price (per MMBtu)	$	6.02			$	6.15	$	5.51
Natural Gas Collars’
Contract Volumes (BBtu/d)	50.0				—		50.0
Weighted Average Ceiling Price (per MMBtu)	$	11.88			$	—	$	11.88
Weighted Average Floor Price (per MMBtu)	$	7.43			$	—	$	7.43
Estimated Price Floor/Ceiling	37-39		%	$6.72-$8.95			35-38		%	$7.11-$10.82
Oil Swaps
Contract Volumes (MBbl/d)	4.0				—		4.0
Weighted Average Price (per Bbl)	$	31.58			$	—	$	31.58
Oil Collars
Contract Volumes (MBbl/d)	5.5				—		5.5
Weighted Average Ceiling Price (per Bbl)	$	65.87			$	—	$	65.87
Weighted Average Floor Price (per Bbl)	$	46.73			$	—	$	46.73
Estimated Price Floor/Ceiling	23-24		%	$40.35-$51.43			41-44		%	$40.35-$51.43

•Approximately 39% hedged in 2006 with a weighted average ceiling price of $10.82 per MMbtu and $51.43 per Bbl

•Completely unhedged in 2007

51

ADDITIONAL REMAINING VALUE

•Unbooked discoveries

•S. Africa (tested 220 MMcfe/d)

•Mackenzie Delta (approximately 200 Bcfe of unbooked reserves)

•Carried interest on frontier acreage

•Gabon (100% carry on seismic and well to be spud in Q1 2006)

•S. Africa deepwater

•Cook Inlet Pipeline Company

•Lantern Drilling Company

•8 company-owned drilling rigs operating in the Permian Basin

•Tax attributes

•$706 Million NOL (including Canadian tax pools of $240 MM)

•Extensive undeveloped acreage and seismic database worldwide

52

VALUE PROPOSITION – Peer Group Comparison

2004 Proved Reserves	2005 Production
[CHART]	[CHART]
2005 EV/Proved Reserves	2005 EV/Production
[CHART]	[CHART]

Note:  Enterprise values as of November 22, 2005.

* Pro forma for Buffalo Wallow acquisition

53

THE “NEW” FST – Summary of Opportunity

•Unlocks intrinsic shareholder value in a tax efficient manner and clarifies the value proposition

•Intensifies focus on two discreet asset bases, each with critical mass and competitive advantage

•Integrates offshore portfolio into high growth vehicle with deepwater exploration potential

•Unleashes Forest’s management to aggressively execute the onshore resource-focused growth strategy

Value Proposition

•Public valuations and M&A transactions support values of $2.97 per proved reserve and $13,629 per flowing Mcfe/d for remaining Forest

•Public valuations and M&A transactions support values of $3.58 per proved reserve and $10,336 per flowing Mcfe/d for Mariner/Spinco

54

EBITDA Reconciliation [LOGO]

	1H05
EBITDA	77.5
Changes in working capital	(14.9	)
Non-cash hedge gain	(2.5	)
Amortization/other	0.6
Stock compensation exp.	9.5
Net interest expense	(3.0	)
Income tax benefit	5.5
Net cash provided by operating activities	72.7

CAUTIONARY STATEMENTS

The United States Securities and Exchange Commission permits oil and gas companies, in their filings with the SEC, to disclose only proved reserves that a company has demonstrated by actual production or conclusive formation tests to be economically and legally producible under existing economic and operating conditions.  We use the terms “probable” and “possible” reserves, reserve “potential” or “upside” or other descriptions of volumes of reserves potentially recoverable through additional drilling or recovery techniques that the SEC’s guidelines strictly prohibit Forest from including in filings with the SEC.  These estimates are by their nature more speculative than estimates of proved reserves and accordingly are subject to substantially greater risk of being actually realized by us.  Investors are urged to consider closely the disclosure in Forest’s Form 10-K for fiscal year ended December 31, 2004, available from Forest at 707 17th Street, Suite 3600, Denver, CO 80202, Attention: Investor Relations.  You can also obtain this form from the SEC by calling 1-800-SEC-0330.

This presentation includes forward-looking statements within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934.  All statements, other than statements of historical facts, that address activities that Forest and Mariner assumes, plans, expects, believes, projects, estimates or anticipates (and other similar expressions) will, should or may occur in the future are forward-looking statements.  The forward-looking statements provided in this presentation are based on management’s current belief, based on currently available information, as to the outcome and timing of future events.  Forest and Mariner cautions that their future natural gas and liquids production, revenues and expenses and other forward-looking statements are subject to all of the risks and uncertainties normally incident to the exploration for and development and production and sale of oil and gas.  These risks include, but are not limited to, price volatility, inflation or lack of availability of goods and services, environmental risks, drilling and other operating risks, regulatory changes, the uncertainty inherent in estimating future oil and gas production or reserves, and other risks as described in Forest’s 2004 Annual Report on Form 10-K as filed with the Securities and Exchange Commission.  Also, the financial results of Forest’s foreign operations are subject to currency exchange rate risks.  Any of these factors could cause Forest’s or Mariner’s actual results and plans to differ materially from those in the forward-looking statements.

These materials are not a substitute for the registration statement that was filed with the Securities and Exchange Commission in connection with the spin-off transaction, or the proxy statement/prospectus-information statement to be mailed to shareholders.  The registration statement has not yet been declared effective.  Investors are urged to read the proxy statement/prospectus-information statement which will contain important information, including detailed risk factors, when it becomes available.  The proxy statement/prospectus-information statement and other documents that will be filed by Forest and Mariner with the Securities and Exchange Commission will be available free of charge at the SEC’s website, www.sec.gov, or by directing a request when such a filing is made to Forest Oil Corporation, 707 17th Street, Suite 3600, Denver, CO 80202, Attention:  Investor Relations; or by directing a request when such a filing is made to Mariner Energy, Inc., 2101 CityWest Blvd., Bldg. 4, Suite 900, Houston, TX 77042-2831, Attention:  Investor Relations.

Mariner, Forest and their respective directors, and executive officers may be considered participants in the solicitation of proxies in connection with the proposed transaction. Information about the participants in the solicitation will be set forth in the proxy statement/prospectus-information statement when it becomes available.

[LOGO]

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