The proposed super-fight between Manny Pacquiao and Floyd Mayweather is getting closer.

Mayweather agreed to terms for the welterweight title bout on Tuesday, multiple sources with knowledge of the negotiations told ESPN.com.

The proposed date is March 13, although there is a chance it could move to May 1, sources said. Mayweather, according to a source close to him, is OK with either date.

Pacquiao and Mayweather have fought recent bouts at catch weights. However if they complete their deal, the bout would be contested at 147 pounds, the maximum for a welterweight fight, a source said.

Top Rank's Bob Arum, who promotes Pacquiao (50-3-2, 38 KOs), was flying to the Philippines on Tuesday night to meet with Pacquiao and try to close his side of the deal.

Arum spent much of Tuesday getting open issues resolved in his negotiations with Golden Boy Promotions CEO Richard Schaefer, who represents Mayweather, sources said. Once Arum was able to do that, he left for the Philippines and is expected back on Monday.

If the HBO PPV fight happens on March 13, it would force the tentative HBO PPV fight between light heavyweights Roy Jones Jr. and Bernard Hopkins to move to another date. Hopkins and Jones both fight Wednesday and must win for their fight to go through.

The site for Pacquiao-Mayweather remains up in the air. There is interest from Dallas Cowboys owner Jerry Jones to bring the fight to his new stadium. There is also interest from venues in Las Vegas, including the MGM Grand (which has hosted several Pacquiao and Mayweather fights), and the Superdome in New Orleans in hosting a fight many believe will break the all-time record for pay-per-view buys, which is the 2.44 million units sold for Mayweather's 2007 split decision victory against Oscar De La Hoya.

The fight moved front and center with heavy public demand for it following Pacquiao's dominant 12th-round knockout of Miguel Cotto to win a welterweight title on Nov. 14. The victory gave Pacquiao a title in a record-breaking seventh weight division and 1.25 million pay-per-view units.

Mayweather (40-0, 25 KOs), who has won titles in five divisions, came out of a brief retirement in September to dominate Juan Manuel Marquez in a fight that generated 1.05 million buys.

Just a few days after Pacquiao's win over Cotto, Arum and Schaefer began negotiations.

One wrench in the talks was the date. Arum, Schaefer and HBO wanted to slot the fight on May 1. However, Pacquiao announced his candidacy for a congressional seat in the Philippines on Tuesday. With the election scheduled for May 10, it rules out a May 1 fight unless Pacquiao runs unopposed. Pacquiao lost the election for a congressional seat in 2007.

If Pacquiao-Mayweather isn't finalized, Arum has talked about matching Pacquiao with junior middleweight titlist Yuri Foreman, which would give Pacquiao an opportunity to win a title in an eighth division. Foreman defeated Daniel Santos to win a 154-pound belt on the Pacquiao-Cotto undercard.

Schaefer has talked about bringing Mayweather to England to match him with Matthew Hatton in the event Pacquiao-Mayweather isn't made. Hatton is the brother of Ricky Hatton, the former junior welterweight and welterweight titlist whom Mayweather knocked out in 2007.

Dan Rafael is the boxing writer for ESPN.com.