The Nepali Congress, one of the country's oldest parties, won 196 of the 575 seats up for grabs in the November 19 polls, according to the final results, pushing the former ruling Maoists into third place.
The Unified Marxist-Leninist (UML) party secured 175 seats in the constituent assembly. The Maoists, who swept Nepal's first post-civil war elections in 2008, were humiliated with a tally of 80 seats.
"Our first priority is to form a consensus (cross-party) government," Nepali Congress general secretary Prakash Man Singh told AFP.
The Maoists, who entered the political mainstream in 2006 after a decade-long civil war, have alleged that the polls were marred by fraud, leaving their participation in the constituent assembly in doubt.
Singh said his party wanted the Maoists on board but added that it was prepared to form a "majority" government with the UML, if they refused to join a cross-party coalition.
UML spokesman, Pradeep Gyawali, told AFP the party was open to a power-sharing deal with the Nepali Congress, but cautioned, "we can't isolate the Maoists, we need to bring them on board".
Senior Maoist leader, Devendra Paudel, told AFP the party would not join a Congress-led government.
"We are considering the option of joining the assembly", Paudel said, adding that the two major parties would still need to seek a consensus on drafting the constitution.
"If the Nepali Congress and UML don't forge an agreement with our party, there won't be a way out," he said.
"The politics will be deadlocked."
