Shares of BP plc shot up 7.57% to close at $38.92 Thursday -- the first day since the April 20 Deepwater Horizon rig catastrophe that the company has been able to choke off all of the oil flowing from the ruptured well.

The success came almost three months after the well began spewing oil into the Gulf of Mexico in the worst environmental disaster in U.S. history. While a tight cap was keeping oil from gushing into the water that has already received tens of millions of gallons of it, the company was waiting to see if it would hold. Engineers will monitor pressure in the well and watch for leaks while they decide their next steps.

BP Vice President Kent Wells told reporters Thursday that at 2:25 CDT oil stopped flowing after engineers had gradually reduced the flow through the 75-ton cap.

"I am very pleased that there's no oil going into the Gulf of Mexico. In fact, I'm really excited there's no oil going into the Gulf of Mexico," Wells said.

The cap is not a permanent fix. BP is continuing work on two relief wells, one of which is expected to permanently bring an end to the leak.

During regular session trading on the New York Stock Exchange Thursday BP shares got as high as $39.81, a substantial climb back from their post-spill nadir of $26.75 but a long way from their April 20 close of $60.48.

Shares of Transocean Ltd., owner of the doomed rig, also climbed Thursday, notching a gain of 4.47% on the New York Stock Exchange to close at $54.70, still a long way from their $92.03 close on April 20.

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