However, before we begin with the opening remarks, I'd like to remind the participants that some of the information in today's call may include forward-looking statements as well as non-GAAP financial measures. A detailed disclaimer and other important information are included in the FAQ document, which is available on our website or upon request. We will welcome your questions after the prepared statements. And now, I'll turn the call over to Simon.Simon Ayat Thank you, Malcolm. Ladies and gentlemen, thank you for participating in this conference call. Third quarter earnings per share from continuing operations, excluding charges, was $0.98 per share. This is an increase of $0.11 sequentially, and $0.28 compared to the same quarter of last year. During the quarter, we recorded $0.02 of charges relating to the continuing integration of Smith and Geoservices. Pretax operating income for Oilfield Services was $1.93 billion. This represents a $182 million sequential increase. Oilfield Services pretax operating income margin improved 77 basis points to 20.2%. Sequential revenue and pretax margin highlights by product group were as follows: Third quarter Reservoir Characterization revenue of $2.5 billion and pretax operating income of $610 million were both flat sequentially. Revenue increases in Wireline and Testing Services due to strong exploration activity were offset in large part by WesternGeco, which was significantly impacted by lower marine vessel utilization on account of seasonal transits and higher docking time, as well as the startup delays in land seismic activities in the Middle East and Asia. Pretax margins were also flat at 24.5%, as the improvements in Wireline and Testing Services due to an improved revenue mix were offset by the impact of the vessel transits and project delays in WesternGeco. Drilling Group third quarter revenue of $3.6 billion were 6% higher sequentially, while pretax operating income improved by almost 14% to $613 million. The revenue increase was led by M-I SWACO on higher activities in U.S. land unconventional plays combined with increases in deepwater activity in the Gulf of Mexico and Brazil for both M-I SWACO and Drilling & Measurements. Pathfinder revenue grew on U.S. land, while other technologies improved following last quarter's spring break-up in Canada. Drilling Group pretax margin improved sequentially by 111 basis points to 16.7% as a result of the higher-margin offshore activities, the seasonal rig count recovery in Canada and better pricing and operating efficiencies in IPM.
Third quarter Reservoir Production revenue of $3.37 billion increased 10.2% sequentially, while pretax operating income improved by 15.5% to $707 million. Revenue increased sequentially, largely due to higher Well Services activities following the spring break-up in Canada. Well Services also had a strong performances on land in the U.S., as well as in Latin America and the Europe/CIS/Africa areas. Reservoir Production pretax margin improved 1 percentage point to 21%, primarily on Well Services increases in Canada and higher asset utilization in U.S. land.Revenue for the Distribution segment increased almost 10% sequentially to $698 million, and the business contributed $31 million of pretax operating income. Now turning to Schlumberger as a whole. It's worth noting that the results in our Europe/CIS/Africa area continue to be burdened by cost relating to the Libya geo market. These costs adversely impacted the quarter's results by just over $0.01 per share. In addition, we lost $0.02 per share on the revaluation of certain foreign currencies denominated assets and liabilities, as a result of the significant strengthening of U.S. dollar against many currencies at the very end of the quarter. The impact of the revaluation process typically does not have a significant impact on us. However, this quarter, the foreign exchange movements in September were quite extraordinary, so I wanted to highlight this to you. Schlumberger effective tax rate, excluding charges, was 23.7% as compared to 24.8% in the second quarter. The ETR for the full year is still expected to be in the mid-20s. We ended the quarter with $6.3 billion of cash and investments on hand and short-term debt of $2.7 billion. Net debt was $5.2 billion at the end of the quarter compared to $4.3 billion at the end of last quarter. Read the rest of this transcript for free on seekingalpha.com