* Talks could resume at 9 pm Tuesday or 9 am Wednesday

* Ukraine says Russia has changed its position

* Russia says made constructive proposal (Adds quotes, detail)

BRUSSELS, June 10 (Reuters) - Eight hours of talks between Russia, Ukraine and the European Commission ended early on Tuesday without a deal on resolving a gas pricing row, raising the risk of supply disruption.

Russia has threatened to cut off gas supplies to Ukraine as early as Tuesday, with possible knock-on effects for EU supplies, over Ukraine's failure to pay its gas bill.

Ukraine's Energy Minister Yuri Prodan said talks, brokered by the European Commission in Brussels, had stumbled over a Russian price mechanism proposal, which would link lower prices to export duty.

"Unfortunately the Russian position regarding the price mechanism has changed," he told reporters, speaking through an interpreter.

Russian Energy Minister Alexander Novak said he had proposed "a very constructive plan, which we believe all stakeholders could and should accept."

He said the plan covered how to make outstanding payments for November and December last year by June 10 and in addition for a certain amount of the debt for April and May to be paid.

A European Commission spokeswoman and Prodan said talks could resume either at 9 pm on Tuesday or at 9 am on Wednesday in Brussels.

(Reporting by Barbara Lewis and Martin Santa; Editing by Kim Coghill)