* Funds the buy with working capital
* Acquisition helps it expand in China and SE Asia (Adds details)
BANGKOK, Sept 30 (Reuters) - Thailand's Siamgas and Petrochemicals PCL said on Wednesday a wholly owned subsidiary would buy a 99 percent stake in Chevron Ocean Gas & Energy Ltd from Chevron China Ltd for $51 million.
Siamgas HK Ltd's acquisition of Chevron Ocean Gas, which operates liquefied petroleum gas (LPG) berths, would help increase sales and distribution of LPG in China and Southeast Asia, Simgas said in a statement.
The acquisition would be financed by working capital, it said. Siamgas, Thailand's number two liquefied petroleum gas firm, vies with energy giant PTT and smaller rival Picnic Corp .
The company more than doubled its earnings last year to 1.09 billion baht, boosted by strong LPG demand from households and manufacturers.
It has customers ranging from car makerMotor to shopping mall operator Central Pattana PCL , and is looking for acquisitions as the downturn throws up bargains.
At 0406 GMT, Siamgas shares were up 0.6 percent at 8.4 baht while the main Thai stock index was down 0.9 percent. (Reporting by Khettiya Jittapong and Viparat Jantraprap; Editing by Alan Raybould)