By Dave Graham

MEXICO CITY, March 15 (Reuters) - A top official from the opposition party leading the race to win the Mexican presidency in July said on Thursday the party could keep Mexico's chief NAFTA negotiator and other officials if talks to rework the trade deal extend into the next government.

Yeidckol Polevnsky, president of the National Regeneration Movement (MORENA) of leftist presidential front-runner Andres Manuel Lopez Obrador, also praised Economy Minister Ildefonso Guajardo, the chief NAFTA negotiator's boss.

Mexico has been locked in talks with the United States and Canada since August to recast the 24-year-old North American Free Trade Agreement after U.S. President Donald Trump threatened to dump it if it was not changed to his liking.

"The negotiating team that Mexico has is a professional, technical team, a very valuable one," Polevnsky told Reuters. "Of course we think it's important to keep it."

Headed by chief negotiator Kenneth Smith, the Mexican team comprises many career civil servants and answers to political appointees Guajardo and his deputy Juan Carlos Baker.

Guajardo, a member of President Enrique Pena Nieto's ruling Institutional Revolutionary Party (PRI), has cast doubt on whether he could continue under a Lopez Obrador presidency.

It would be unusual for a new government, especially one led by a staunch critic of the PRI, to retain a minister with Guajardo's political background. Lopez Obrador unveiled his own planned cabinet last December.

The next president takes office on Dec. 1, and the top jobs would ultimately be up to Lopez Obrador, Polevnsky said.

Still, she called Guajardo a "very valuable" official and indicated the door was open to Smith and others staying on to continue the negotiations under a MORENA government.

"Kenneth, of course. He's extremely valuable," she said, adding "Baker too" when asked if Guajardo's deputy might also be retained. "There are a lot of very valuable people."

Guajardo on Thursday urged officials to wrap up the talks quickly, but conceded that was unlikely to happen before the regular session of the Mexican Congress ends on April 30.

That raises the possibility of the renegotiation extending well into 2018 or beyond.

Guajardo, speaking in Sao Paulo and asked whether he would stay on, told Reuters: "That will depend on who wins the election and if they decide to invite us."

Lopez Obrador, whose criticism of Pena Nieto's economic reforms has alarmed influential sections of the business community, has expressed support for NAFTA. (Reporting by Dave Graham Additional reporting by Daniel Flynn in Sao Paulo Editing by Leslie Adler)