KIEV, Feb. 9 – Ukraine on Wednesday postponed indefinitely an amicable agreement with a consortium led by U.S. oil company Vanco Energy, further delaying development of massive oil and gas fields in the Black Sea.

The agreement was originally supposed to be approved at a meeting of the Cabinet of Ministers on Wednesday, but was eventually taken off the agenda.

Fedir Yaroshenko, the finance minister, said the deal had been postponed because of renewed discussions over terms of the amicable agreement.

This is the third time that the agreement is being delayed since the talks between Ukraine and Vanco have resumed last year.

The agreement was earlier delayed because Vanco had been apparently demanding more than $100 million in compensation from the government for canceling the original production-sharing agreement, or PSA, in May 2008, according to government officials.

The sudden delay comes as former Prime Minister Yulia Tymoshenko, now the leader of an opposition group, has Wednesday called for a scrutiny of the agreement by Parliament and by law enforcement authorities due to unspecified corruption concerns.

Tymoshenko, whose government had actually cancelled the PSA with Vanco in May 2008, called the discussed amicable agreement a “tragedy” for allegedly channeling massive oil and gas resources to people that she says are affiliated with the authorities.

“If this tragedy has taken place at the government meeting today, than a special session of Parliament must be dedicated to it,” Tymoshenko said. “Special reports by government officials must be made and special criminal cases must be opened by the Prosecutor General’s Office.”