BANGKOK: Lawmakers in Thailand on Tuesday endorsed a veteran politician and leader of a small party as the new speaker of the lower house, signalling a detente in a row between the two biggest players as they seek to form a new coalition government.

The nomination of Wan Muhamad Noor Matha, 79, was widely seen as a compromise between alliance partners Move Forward and Pheu Thai, which have sparred for weeks over the speakership, a post crucial to the passage of bills and the timing of key legislative votes.

Wan Noor represents the Prachachart Party, a junior member of an eight-party alliance dominated by Move Forward and Pheu Thai, which together won the lion's share of the seats in the May 14 election, thrashing conservative parties allied with the royalist military.

A southerner and ethnic Malay Muslim in predominantly Buddhist Thailand, Wan Noor has served previously as house speaker and has close ties with Pheu Thai's leadership. He was the only nomination and his selection is pending royal approval.

"I will conduct duties fairly ... with transparency in considering draft laws and petitions to improve the lives of all Thais," Wan Noor told the house.

Among his first tasks will be to table a joint vote of the 750-member bicameral parliament on a prime minister to form the next government.

The alliance, which has 312 seats, is backing Move Forward leader Pita Limjaroenrat. To become premier, a candidate needs 376 votes, or more than half.

It is unclear what the alliance's next move will be if Pita fails. He needs 64 votes from rival parties or from members of a conservative-leaning Senate that has clashed with Move Forward over its anti-establishment agenda.

Move Forward were the surprise election winners after mobilising massive youth support on social media behind ambitious plans to tackle business monopolies, keep the army out of politics and reduce the severity of punishments for insulting the powerful monarchy.

Pita on Tuesday said Move Forward had "retreated" on its position having been assured by Wan Noor that its policies would be supported. The two deputy speaker positions will go to Move Forward and Pheu Thai.

"This decision is not about me or the party, but the mission of restoring democracy," Pita said on Facebook. "In the uncertainty of Thai politics, principle is more important than the personality."

Titipol Phakdeewanich, a political analyst at Ubon Ratchathani University, said Move Forward's relent on the speaker showed its path to office faced resistance because of its determination to pursue its liberal agenda.

"The party is seen as an enemy by many of the conservatives," Titipol said, adding Pita's fate was in the hands of a military-appointed upper house.

"What we do not know is whether Pheu Thai will switch sides if the initial vote for Pita fails."