U.S.-listed shares of BP Plc jumped 7.6 percent on Thursday after a company executive said no oil was leaking from its blown-out well into the Gulf of Mexico for the first time since late April.
Kent Wells, BP's senior vice president of exploration and production, told a media briefing that a new cap had completely shut in the flow of crude oil while the company conducts a critical pressure test on the stricken well.
Investors are closely watching the company's efforts to stop the crude flow, which has caused the worst U.S. environmental disaster. BP's setbacks and progress in recent weeks have caused big swings in the stock price.
BP shares ended at $38.92, up $2.74, on the New York Stock Exchange. After the close of regular trading, the company's stock rose further to $39.15.
News that the crude stopped flowing also gave a lift to other so-called spill stocks.
Shares of Anadarko Petroleum Corp , a U.S. oil and gas company that owns a 25 percent stake in the ruptured well ended 3.2 percent higher at $49.08. U.S.-listed shares of Transocean , which owned the rig that sank in the April 20 accident, ended the session up 4.5 percent at $54.70.
(Reporting by Caroline Valetkevitch in New York and Anna Driver in Houston; Editing by Kenneth Barry and Steve Orlofsky)