Ultra Petroleum Corp. has sold Sino-American Energy Co. to SPC E&P (China) Pte Ltd. in a stock transaction worth $223 million.

The Houston exploration and production company said Sino-American represented all of its interests in Bohai Bay, China, as well as all of Ultra’s international assets and about 1 percent of its year-end 2006 proved reserves.

The sale is expected to close during the fourth quarter of 2007.

With the sale, Ultra said it would be able to focus on its Pinedale Field, Wyo., assets.

SPC E&P (China) Pte Ltd. is a wholly-owned subsidiary of Singapore Petroleum Co. Ltd.

Jefferies Randall and Dewey acted as financial advisers for Ultra in this transaction.