The Russian and Ukrainian prime ministers...

Dmitry Peskov, the spokesman for Russian premier Vladimir Putin, said Putin and Mykola Azarov on Friday discussed cooperation, including in the energy sphere, on the phone.

Ukrainian President Viktor Yanukovych, who was inaugurated in February, is seeking to revise the long-term gas deal signed by then prime minister Yulia Tymoshenko and Putin in early 2009, which increased the price Ukraine paid for Russian gas, further straining the country"s troubled finances.

In return for cheaper gas, Ukraine could offer Russia a stake in its gas transportation system, which currently carries about 80% of Russian natural gas exports to Europe.

MOSCOW/KIEV, April 10 (RIA Novosti)