Ukraine's January deal with Russia, which ended a row over gas prices that had briefly disrupted European supplies, involved a little-known intermediary, RosUkrEnergo.
Under the deal Ukraine agreed to pay nearly double what it had been paying for Russian and Turkmen gas supplies.
Tymoshenko said in an interview published today she was convinced the three countries should conclude an agreement directly, without "shady or semi-shady intermediaries."
She said she plans to start gas talks with Russia in a week.
Tymoshenko's earlier call for deep revisions in the January gas agreement sparked a sharp warning from Russia's Gazprom not to reignite the gas dispute.
(compiled from agency reports)