July 29, 2010: OSLO, NORWAY – Petroleum Geo-Services ASA (“PGS” or the “Company”)
reported an EBITDA of $71.4 million (33 percent margin) in Q2 2010. The results were
impacted by significant investments in vessel upgrades and repositioning of vessels, as
earlier indicated. The upgrades further strengthen PGS’ fleet as the most cost effective
in the industry.

§ Group performance: Q2 2010 revenues were $214.9 million, with a corresponding EBIT of
$5.3 million, compared to revenues of $294.3 million in Q2 2009 and an EBIT of $32.9
million.

§ Marine: Q2 2010 revenues were lower compared to the same period last year, primarily
driven by more time spent steaming and at yard, lower prices for Marine contract work
with 2009 having benefited from activity priced before the credit crunch, and lower
MultiClient pre-funding revenues. Industry capacity additions scheduled for 2010
continue to put pressure on conventional streamer pricing.

§ Most of the 2010 GeoStreamer capacity sold: Strong customer interest for GeoStreamer
continues. Ramform Valiant was equipped with GeoStreamer in June and Ramform Explorer
completed the same upgrade in July.

§ GeoStreamer price uplifts: Relative pricing differentiation for GeoStreamer work
continues to improve with margins of more than 1000 basis points above conventional
streamer margins.

§ Order book increasing: Order book increased by approximately $90 million from Q1 2010
and total order book is now $499 million.

§ Two break-through contracts for OptoSeis: PGS has signed an agreement with Petrobras
to install a fiber-optic system at the Jubarte field, and a collaboration agreement with
Shell to develop an onshore fiber-optic exploration and reservoir monitoring system.

§ More flexible credit facility: The Company amended its revolving credit and Term Loan
B facility in May 2010 to increase financial flexibility.

§ Negative net financial items: Foreign exchange fluctuations and amendment and
redemption of credit facilities resulted in a cost of $18.2 million in Q2 2010.

§ Organizational changes implemented: Following sale of the Onshore business PGS
implemented its new organizational structure.

§ EBITDA guidance maintained: The Company maintains its full year EBITDA guidance of
$450 million, supported by GeoStreamer success and increased MultiClient pre-funding
revenues in the second half, offset by a weak contract market for conventional streamers
and some MultiClient late sales uncertainty.

Jon Erik Reinhardsen, Chief Executive Officer and President of PGS, commented:

“The upgrade of Ramform Explorer to become one of the most efficient vessels in the
industry will together with the GeoStreamer upgrade of Ramform Valiant and delivery of
the new PGS Apollo pave the way for increased efficiency and reduced exposure to the
industry cycles. The second quarter was impacted by repositioning of vessels and
significant investments in vessel and GeoStreamer upgrades. New industry capacity will
continue to put pressure on pricing in the second half, but we remain on track to meet
our current full year EBITDA guidance.”

Key Financial Figures Quarter ended Six months ended June 30, Year ended December 31, 2009
(In millions of dollars, except per share data) June 30, Audited 1)
2010 2009 2010 2009
Unaudited Unaudited Unaudited Unaudited
Revenues from continuing operations $ 214.9 $ 294.3 $ 474.3 $ 685.1 $ 1,350.2
Adjusted EBITDA (as defined) 71.4 154.1 170.7 360.5 672.1
EBIT excluding special items 2) 5.3 81.2 40.1 236.3 386.9
EBIT 5.3 32.9 39.6 137.5 233.3
Income (loss) before income tax expense (27.4) 40.2 (12.4) 129.8 228.1
Net income (loss) to equity holders (22.3) 41.0 (6.1) 95.2 165.8
Basic earnings per share ($ per share) (0.11) 0.22 (0.03) 0.53 0.88
Diluted earnings per share ($ per share) (0.11) 0.22 (0.03) 0.53 0.88
Net cash provided by operating activities 63.8 208.1 179.3 353.5 676.1
Cash investment in MultiClient library 51.7 56.7 103.8 101.6 183.1
Capital expenditures 52.7 56.8 100.6 150.5 231.2
Total assets (period end) 2,690.4 3,132.4 2,690.4 3,132.4 2,929.4
Cash and cash equivalents (period end) 159.8 168.1 159.8 168.1 126.0
Net interest bearing debt (period end) $ 616.3 $ 962.1 $ 616.3 $ 962.1 $ 774.0

1) Financial information for the full year 2009 is derived from the audited financial
statements as presented in the 2009 Annual Report.
2) Impairment charges of $0.5 million in Q1 2010 and $153.6 million for the full year
2009.

Complete Q2 2010 earnings release can be downloaded at www.newsweb.no
http://www.newsweb.no/ or www.pgs.com http://www.pgs.com/

FOR DETAILS, CONTACT:
Tore Langballe, SVP Corporate Communications

Phone: +47 67 51 43 75

Mobile: +47 90 77 78 41

Bård Stenberg, Investor Relations Manager

Phone: +47 67 51 43 16

Mobile: +47 99 24 52 35

US Investor Services

Phone: +1 281 509 8712

This information is subject of the disclosure requirements acc. to §5-12 vphl (Norwegian
Securities Trading Act)