New York City mayoral candidate Bill Thompson has conceded the Democratic primary race to Bill de Blasio, averting a potential runoff.
Thompson says continuing the race would be a disservice to supporters, Democrats and the people of New York City in explaining withdrawing his bid for mayor.
He has endorsed Bill de Blasio as the Democratic nominee.
The potential Oct. 1 runoff had loomed as another act in the Democratic drama over choosing a successor to three-term Mayor Michael Bloomberg -- a drama that would keep Democrats tilting at each other while Republicans and independents looked ahead to the Nov. 5 general election.
In unofficial returns with 99 percent of precincts reporting, de Blasio had had 40.3 percent of the vote -- slightly more than the 40 percent threshold needed to win outright. Thompson was at 26.2 percent.
A runoff had long been expected in the crowded Democratic race. But after last week's unofficial returns put de Blasio above the 40 percent mark, Thompson faced pressure to concede and spare the party further division ahead of the general election.
(Read more: NYC's new mayor to face day of reckoning on labor deals)