But members of the delegation, led by first deputy prime minister Yuri Maslyukov, expressed optimism that an economic reform programme potentially worth billions of dollars would be agreed this week.

``There are no principal differences'' between Russia and negotiators from the International Monetary Fund and World Bank, finance minister Mikhail Zadornov told reporters.

He was speaking after a meeting with IMF officials that lasted about two hours longer than expected.

``A few disagreements remain, and they are being sorted with every new meeting. ... They touch on taxes, the foreign exchange regime and other concrete issues,'' Zadornov said.

Maslyukov added that other issues still under discussion included Russia's banking system and its bankruptcy laws.

But he said:``We still think we can achieve our goal to discuss and agree on all outstanding questions by the end of the week.''

The delegation declined to say how much Russia wanted to get from the IMF, although officials earlier said Russia at minimum is seeking $4.8 billion -- enough to pay what it owes the IMF this year.