Roman Zvarych, presiding over the session, said all the 228 members of the Yulia Tymoshenko bloc and pro-presidential Our Ukraine-People's Self-Defense bloc (156 and 72 respectively) had put their signatures under the coalition deal. Several members of the president's bloc had previously threatened to vote down a coalition with Tymoshenko.
The coalition agreement states that Tymoshenko will be put forward as prime minister. The candidacy will be submitted to her 2004 "orange revolution" ally President Viktor Yushchenko, and requires his approval before a government can be formed.
Tymoshenko served as premier in 2005, but was fired by Yushchenko after less than eight months in office, amid political in-fighting.
Under the Ukrainian Constitution, lawmakers have 60 days from the September 30 parliamentary elections to form a government.
In line with the coalition deal, the Our Ukraine-People's Self-Defense bloc is entitled to pick a parliamentary speaker. Until recently Vyacheslav Kyrylenko, the head of the bloc's political council, was considered the most likely candidate, but before Thursday's session reports emerged that Kyrylenko had proposed acting foreign minister Arseniy Yatsenyuk for the post.
The leader of Our Ukraine-People's Self-Defense, Yuriy Lutsenko, said he viewed Kyrylenko as the strongest candidate for speaker.
During the early elections to Ukraine's parliament, the Supreme Rada, the Party of Regions led by Yushchenko's arch rival Prime Minister Viktor Yanukovych gained the largest number of votes. However, the "orange" factions were able to unite to amass a narrow majority.
The head of the presidential office, Viktor Baloga, said the president is convinced that nothing will hold back formation of a democratic coalition.
"The president is fully convinced that there are no obstacles on the way to establishing a democratic coalition and forming an effective government," Baloga said.
The coalition will consider candidates for speaker and prime minister on Friday.
