ISTANBUL - Turkey will reduce the amount of oil it buys from Iran by around 10 percent, Turkish Energy Minister Taner Yildiz said on Friday, a week after Washington warned Iran's customers they could be subject to US sanctions unless they significantly cut purchases.Turkey will partly replace the oil with 1 million tons it expects to buy from Libya, Yildiz told reporters. The country is also in talks with Saudi Arabia on spot oil purchases and longer term contacts, Yildiz added. Tupras is the main Turkish customer, currently buying some 30 percent of its crude oil from Iran, and it has an 9 million tons annual purchase contract.Koc Energy Group Chairman Erol Memioglu told reporters last month that the existing Tupras oil contract with Iran ends in August.He said that he expected more clarity on the details of the sanctions in May, before Washington's measures on oil-related transactions take effect on June 28.Both the United States and the European Union have imposed unilateral sanctions against Iran's financial and energy sectors over its nuclear program, whereas Turkey has said it is only compelled to observe the softer UN sanctions.Trade between Turkey and Iran has risen sharply over the past decade, leading to Turkey being regarded as a possible weak link in the international sanctions against Iran.Turkey has struck a new contract to buy oil from Libya, and has held talks with Saudi Arabia about possible supplies over the past few months.Iran says its nuclear program is solely for civilian purposes, and denies that it is building weapons. A meeting between Iranian nuclear negotiators and representatives of six major powers is expected on April 13, with Istanbul a possible venue for the talks.Tupras shares were little moved after the announcement, up 0.9 percent at 44.9 lira, by 12:07 GMT."We plan to increase the number and the route of countries we buy oil from," Yildiz said.Turkey imports around 200,000 barrels per day of oil from Iran, representing 30 percent of its total imports and more than 7 percent of Iran's oil exports.Having been omitted from a list of countries granted exemptions by Washington, Turkey remained hopeful of obtaining a waiver to avoid U.S. financial sanctions.The United States exempted Japan and 10 EU nations from sanctions because they have significantly cut purchases of Iranian crude oil, but left Iran's top customers China and India exposed to the possibility of such steps.Turkey's sole refiner Tupras, a unit of Koc Holding, said in a statement to the Istanbul stock exchange that it would cut its purchases of Iranian crude by 20 percent.