Shares of ATP Oil & Gas Corp. rose Tuesday after the U.S. allowed it to resume deepwater drilling operations in the Gulf of Mexico, according to the Associated Press. ATP, based in Houston, was one of 13 companies that were granted government clearance for projects that were put on hold last year during the U.S. moratorium on deepwater drilling. ATP''s rise outpaced other cleared companies, including Chevron Corp. and Royal Dutch Shell, because they''re not as reliant on Gulf of Mexico drilling. Prior to the moratorium, ATP had planned to complete two more deepwater wells from its Telemark Hub project in the second half of 2010. The government''s clearance will allow ATP to complete one of those wells by the end of the first quarter and the second will be completed by the end of the second quarter, said Curtis Trimble, an analyst with MKM Partners.