Manny Pacquiao reluctantly will look for another opponent for his next bout after promoter Bob Arum’s deadline for a deal with Floyd Mayweather Jr. passed Saturday without a word from Mayweather.

In the latest improbable twist in the torturous negotiations for the most tantalizing prospective fight in boxing, Arum said Mayweather’s camp simply hasn’t responded to a contract proposal with no obvious points of contention.

Pacquiao already has agreed to extensive drug testing and an equitable split of the earnings from what’s likely to be the richest fight in boxing history.

“Floyd, for whatever reason — and I’m sure he has some valid reason — didn’t want to commit,” Arum said.

Although Arum was careful not to criticize Mayweather, saying the fighter who calls himself Money could take the incredibly lucrative offer at any point in the next week or so, Arum plans to open discussions with Antonio Margarito and Miguel Cotto for a fight in November.

“(Pacquiao-Mayweather) is dead when we conclude a deal for Manny’s fight in November,” Arum said. “Then we’re contractually bound to that fight, and we would look to do a deal with Floyd for next year. If Floyd emerged and said he wanted to do the fight (in November), then there would be nothing opposed to doing the fight.”

Arum claims he couldn’t wait any longer to start the time-consuming process of putting together a fight for Pacquiao, whose personal schedule has tightened up with his election to congress in his native Philippines this year. Arum said Top Rank needs several months to put together television deals and publicity tours for the bout.

Pacquiao and Mayweather are their sport’s top two stars, and a meeting likely would be worth more than $40 million to each fighter.