Ukrainian Prime Minister Viktor Yanukovych presented his government's resignation on Friday at the first session of a new parliament following September elections.
"I announce the renunciation of the powers of the Ukrainian government," Yanukovych told parliament.
Yanukovych's announcement, in line with procedures set out in the constitution, followed the swearing in of all 450 new deputies in the parliament of this former Soviet republic, a ceremony watched by two former Ukrainian presidents.
Yanukovych earlier voiced hope that his Regions party would be included in a new governing coalition as formal talks on creating a coalition government got under way.
Analysts say the more likely outcome is an "orange" coalition of President Viktor Yushchenko's Our Ukraine-Self Defence party and the Yulia Tymoshenko Bloc, groups that spearheaded the peaceful Orange Revolution of 2004.
Ukraine held snap elections on September 30 in an effort to resolve months of wrangling between Yushchenko, who supports full integration with the West, including the NATO military alliance, and the more pro-Russian Yanukovych.
Yushchenko has himself been reticent on the formation of a new government, earlier calling for Yanukovych's Regions party to be included.
One leader of Our Ukraine-Self Defence, Vyacheslav Kirilenko, told Interfax news agency that a coalition agreement could be signed as early as Friday.