TEHRAN, Oct 2 (Reuters) - Iran, the world’s fourth-biggest oil exporter, has boosted oil export earnings in non-U.S. dollar currencies to 85 percent, an Iranian oil official said on Tuesday.

“Iran is selling about 85 percent of its oil in the non-dollar currencies,” state television quoted Mohammad Ali Khatibi, deputy director of international affairs at the state oil company National Iranian Oil Company (NIOC), as saying.

Last week, Hojjatollah Ghanimifard, international affairs director of NIOC told Reuters: “With the arrangements we’ve made with our Asian customers, hopefully by the end of October we will have around 80 percent of our export revenue in currencies other than the dollar.” Iran, embroiled in a standoff with the West over its nuclear programme, has for nearly two years been reducing its exposure to the dollar, saying the weak U.S. currency is eroding its purchasing power.

“Currently, about 65 percent of Iran’s crude exports are based on euro and 20 percent based on yen,” said Khatibi.

In July, NIOC made an official request to customers in Japan, which imports more than 300,000 barrels per day (bpd) of Iranian crude, to pay in yen.

A switch in payment by Japan's Nippon Oil 5001.T and other Japanese refiners to yen had already pushed Iran's non-U.S. dollar income to more than 70 percent in September.

Iran’s total crude oil exports are around 2.3 million bpd.