The independent energy company Apache Corp. says it is buying Mariner Energy for $2.7 billion to extend its deepwater projects in the Gulf of Mexico.

Apache is offering cash and stock worth about $26.22 per share for Mariner Energy, a premium of 45 percent over Wednesday's closing price.

Mariner's shares climbed 38.5 percent to $25.05 in premarket trading.

Apache, based in Houston, is also assuming $1.2 billion in debt.

Mariner, also based in Houston, has principal operations in the Permian Basin, the Gulf Coast and the Gulf of Mexico.

Apache operates in the U.S., Canada, Egypt, the United Kingdom North Sea, Australia and Argentina.