KIEV, Sept. 30 - Ukrainian opposition leader Yulia Tymoshenko, who is likely to become the next prime minister after the Sept. 30 snap election, pledged to renegotiate a key natural gas supply deal with Russia.

The group led by Tymoshenko and President Viktor Yushchenko’s Our Ukraine-People’s Self-defense were likely to score a victory and form the next government, three independent exit polls suggested Sunday.