Schlumberger Ltd , the world's largest oilfield services company, posted a 33 percent jump in quarterly profit on brisk activity in North America land markets, but said it did not expect drilling to resume in the Gulf of Mexico this year.

With its global reach, Schlumberger is not as exposed to the Gulf of Mexico as some of its peers, with only about 5 percent of its revenue from that region, far less than its nearest rival, Halliburton Co .

The BP Plc oil disaster in April led to a regulatory crackdown as the U.S. government froze activity in the Gulf of Mexico through the end of November while it crafts new drilling safety rules.

Schlumberger's second-quarter net profit rose to $818 million, or 68 cents per share, from $613 million, or 51 cents per share, a year before. The earnings were in line with analysts' average forecast, according to Thomson Reuters


Revenue rose 7.4 percent to $5.94 billion.

The recovery in world demand for oil has been reasonably robust and current forecasts for the coming year remain consistent with slowly increasing levels of exploration and production activity, Chief Executive Andrew Gould said in a statement.

Pre-tax profit at the oilfield service business climbed 5 percent from a year earlier, to $1.07 billion, with gains in well servicing in the North American land market as well as gains in Russia, Latin America and the North Sea.

The company's WesternGeco seismic arm, which maps oil and gas reservoirs, saw pretax earnings drop 52 percent as activity fell off from the strong first quarter, the company said.

The seismic unit's outlook will be reliant on the uncertain market in the Gulf of Mexico, it said.

Schlumberger said last month that it had accelerated a review of its U.S. operations due to the knock-on effect of the Gulf spill.

Halliburton reported better-than-expected quarterly profit on Monday thanks to strength in U.S. onshore drilling, but said earnings for the rest of the year would be reduced by 5 cents to 8 cents per share due to the Gulf of Mexico impact.

Halliburton said on Monday its quarterly profits would be 5 cents to 8 cents per share weaker this year due to the Gulf of Mexico impact, but reported a better-than-expected profit thanks to strength in U.S. onshore drilling.

Schlumberger's involvement in the BP well blow-out has been the subject of media speculation, given that its wireline services crew, which runs well tests, left the rig the day it exploded and sank.

Shares of Schlumberger, down 5.8 percent this year, dropped 2.1 percent in premarket trade.

(Reporting by Matt Daily; Additional reporting by Braden Reddall in San Francisco; Editing by Lisa Von Ahn and John Wallace)