An investment arm of the Abu Dhabi government will spend about $776 million to buy one-fifth of Cosmo Oil Co, becoming the top shareholder in Japan's fourth-largest oil company.

International Petroleum Investment Co (IPIC) is rapidly expanding into the global oil and natural gas sectors. IPIC invests in oil and gas related assets for the Abu Dhabi government, which controls more than 90 percent of oil reserves in the UAE.

Japan buys about 40 percent of the UAE's oil exports.

"The purchase reflects Japan's strategic importance to the UAE," an IPIC source told Reuters.

Japan has seen a drop in the amount of oil it buys as consumers move to fuel-efficient cars. The International Energy Agency said in August oil product demand in Japan for June fell for the fifth month in a row, down 2.9 percent on annual basis.

But Cosmo was focusing on the export market for expansion. The company aims to double its oil product exports to 4 million kilolitres per year, a Cosmo company official said on Tuesday.

IPIC was eying the growth potential of Cosmo's fuel product exports to the west coast of the United States, the IPIC source said.

"IPIC finds Cosmo's US strategy particularly interesting and it has growth potential," the source said.

Cosmo operates a US subsidiary on the West Coast with sales of 400,000 to 600,000 kilolitres per year of diesel oil, according to its Web site.

IPIC was also eyeing international joint venture opportunities with Cosmo, the IPIC source said.

"There are a lot of opportunities we have identified internationally," the source said declining to be more specific.

"We see many opportunities for additional investment with Cosmo in the Asia-Pacific region," Khadem Al-Qubaisi, IPIC's managing director said in a statement.

Cosmo said it would issue 176 million new shares to Infinity Alliance Ltd, a wholly owned unity of the IPIC, for 510 yen per share, a discount of 6 percent from Tuesday's closing price of 544 yen.

The Japanese company will raise about 89.2 billion yen through the share issue. Infinity Alliance will become the biggest shareholder, owning 20.76 percent of the Japanese company after the acquisition of the new shares. The paid-in date is October 5.

Cosmo Oil said the share issue would strengthen its financial health and help it expand.

Cosmo Oil's President Yaichi Kimura told reporters that although IPIC would have voting rights and will accept two IPIC executives to its board, the company's business strategies will remain unchanged.

He added that the deal will lead to steady crude supplies from the UAE, which supplies about 25 percent of Cosmo's crude imports. - Reuters