PHNOM PENH, Sept 16 (Reuters) - Japanese oil and gas firm Mitsui Oil Exploration Co has applied to Cambodia for exploration rights in an area of the Gulf of Thailand claimed by both Cambodia and Thailand, officials said on Wednesday.
Cambodia's government spokesman, Ieng Sophalleth, said Mitsui's chairman, Yoshiyuki Kagawa, "assured the prime minister during a meeting on Tuesday that the company was determined to invest in block four" in the contested area.
"Prime Minister Hun Sen told the company's chairman that he welcomed all companies to join in the bidding process in a transparent way," Sophalleth told Reuters by phone.
Mitsui Oil Exploration Co is a unit of Japanese trading house Mitsui & Co Ltd (8031.T).
Hang Chuon Naron, secretary general at the finance ministry, said the government would take some time before granting any concession.
"And Mitsui will have to talk with the Thai side at a later stage on the oil exploration and production," he told Reuters.
Cambodia's exploration area covers 37,000 square km (14,300 sq miles). Another 27,000 square km (10,400 sq miles) thought to be rich in oil and gas deposits is claimed by Thailand.
In February Hun Sen said, referring to the disputed area, that Cambodia's government would "adhere to principles of international law, the win-win policy and good neighbourliness in resolving various issues with all parties involved".
Cambodia does not yet produce oil. Chevron Corp (CVX.N) is the operator of Block A in the Gulf of Thailand but is unlikely to produce oil before 2010 at the earliest. (Reporting by Ek Madra; Editing by Alan Raybould)