TOKYO, July 28 (Reuters) - Japanese oil refiner TonenGeneral Sekiyu has bought its first oil from Iran since becoming independent from U.S. oil major Exxon Mobil Corp , three industry sources familiar with the matter said.

The company bought the Iranian spot cargo through a trading house due to attractive pricing and the shipment arrived Japan earlier this month, the sources said.

TonenGeneral, formerly a unit of Exxon Mobil, previously could not buy Iranian oil due to its affiliation with the U.S. oil company.

TonenGeneral bought a controlling stake in itself from Exxon in 2012, reducing Exxon's stake from 50 percent to 22 percent as the oil major pulled back from Japan due to the country's declining oil demand.

Exxon Mobil has since sold that remaining stake in Japan's second-biggest oil refiner by capacity, shedding its last holding in TonenGeneral by early this year.

TonenGeneral Sekiyu, an aggressive buyer of cheaper crude grades, is known for having one of Japan's highest ratios of spot crude compared to term volumes, and will consider buying more Iranian oil depending on economics, the sources said.

A TonenGeneral spokeswoman said the company cannot comment on the spot crude purchase.

Iran has been regaining market share faster than analysts had expected after sanctions were lifted in January, and its exports are projected to be above 2 million barrels per day for a fourth month in July.

By Reuters