LAS VEGAS -- Shane Mosley is having second thoughts about taking a $4.25 million purse to fight Oscar De La Hoya. And promoter Bob Arum is having second thoughts about Mosley fighting De La Hoya at all.

With a planned Sept. 13 rematch between the two fighters in jeopardy, Arum said Tuesday that De La Hoya will fight a rematch with Fernando Vargas if Mosley doesn't sign a contract his agent agreed to.

"If he doesn't want to fight De La Hoya, God love him,'' Arum said. "I'm not losing any sleep over it.''

Mosley was supposed to fight De La Hoya in a rematch of their 2000 welterweight title bout, a fight that Mosley won by split decision.

De La Hoya would get $12 million for the fight, while Mosley's agent, Barry Frank, negotiated a $4.25 million purse for his fighter. But Mosley says he is worth far more than that and will not sign a contract for the negotiated purse.

"I think I'm worth at least $8 million,'' Mosley told The Associated Press. "I'm very adamant about that.''

Arum is just as adamant that Mosley won't get a penny more than the negotiated purse. He says he is ready to sign Vargas for a rematch with De La Hoya if Mosley doesn't sign.

"If they don't deliver me a contract next week signed by Mosley there's no Mosley fight. It's as simple as that,'' Arum said.

In boxing, of course, nothing is ever that simple. Complicating the matter is that Mosley is scheduled to fight Raul Marquez on Saturday in an Arum-promoted bout designed to showcase him for the De La Hoya rematch.

Arum said the De La Hoya fight was always contingent on Mosley beating Marquez. Now, he says, Mosley must also look good in doing so.

"If he's saying he doesn't have a deal it's more than just winning,'' Arum said. "Otherwise forget it. I'm outta here.''

Mosley wouldn't seem to be in a great bargaining position. He lost his last two fights to Vernon Forrest and has never been a proven ticket seller.

And Arum has an eager Vargas waiting in the wings to take a rematch of his Sept. 14 knockout loss to De La Hoya if Mosley backs out.

"All the casinos think a Vargas rematch is a bigger fight anyway,'' Arum said. "I feel in good faith we made a proposal to Mosley and his agent accepted. We've already negotiated this fight.''

Arum said the only way Mosley would get more than $4.25 million would be to take a piece of De La Hoya's share of the purse, something that isn't going to happen.

"I already asked Oscar about that,'' Arum said. "He said no.''

Frank said he planned to meet with Mosley after the Marquez fight and figure out what to do.

"Maybe we can sign it and maybe we can't,'' Frank said. "We're not even going to discuss it until after this fight.''

Frank said Mosley was happy with the purse when it was first negotiated but later changed his mind.

Mosley said he wanted to focus on Saturday's fight, his first at 154 pounds, and didn't want to discuss De La Hoya or the contract. Still, he said, he felt wronged.

"I hold a victory over De La Hoya, that's all that matters to me,'' he said. "I just want things to be fair, that's all.''