The party allied to ousted Prime Minister Thaksin Shinawatra won Thailand's general election by a wide margin, the Election Commission confirmed from final results Tuesday.
The opposition Pheu Thai party led by Thaksin's sister Yingluck Shinawatra won 265 of 500 parliamentary seats, well over the majority needed to form a government.
The ruling Democrat party of Prime Minister Abhisit Vejjajiva won 159 seats in Sunday's election, the commission said.
The vote was a major rebuke to the elite establishment and army that overthrew Thaksin in a 2006 coup, an event that triggered years of political turmoil and sporadic violence.
Yingluck has shored up her party's resounding victory by forming a ruling coalition with four smaller parties and vows to pursue national reconciliation. The military eased concerns of renewed turmoil by declaring acceptance of Pheu Thai's sweeping win.
U.N. Secretary-General Ban Ki-moon "welcomes the orderly conduct of the parliamentary elections in Thailand and the promise by all parties to respect the will of the Thai people as expressed through the democratic process," U.N. spokesman Martin Nesirky said.
"The secretary-general hopes that the elections mark an important step towards genuine reconciliation, long-term stability and consolidation of democratic norms in the country," Nesirky said. "He looks forward to working with the incoming government and all parties in Thailand."
The lower house of Parliament has 30 days to convene and another 30 days from its first session to officially select a prime minister. Pheu Thai's speedy agreement on coalition partners indicates a new government can be expected ahead of the deadlines.
Thaksin is barred from politics and lives in exile in Dubai to escape a two-year prison term on a graft conviction that he says is politically motivated.