Gegard Mousasi, one of the best middleweight mixed martial artists in the world, has signed a multifight deal with Bellator MMA.

Mousasi (42-6-2) confirmed the deal during an appearance on "The MMA Hour." Terms of the agreement were not disclosed, and his promotional debut has not yet been announced.

The 31-year-old middleweight fought out his exclusive UFC contract in April. The two sides entered negotiations on an extension, but ultimately Mousasi opted to sign with Bellator.

Fighting out of Amsterdam, Mousasi had expressed some complaints about his pay near the end of his UFC deal. He pointed to specific opponents he'd beaten previously who were still earning more than he was.

On Monday, he told ESPN he is "very happy" with the Bellator contract, and added it will pay him a flat rate every time he fights -- as opposed to the show-and-win money system the UFC traditionally favors.

"I show up and I get paid," Mousasi told ESPN. "With the UFC, they say, 'If you're a champion, we'll pay you well.' They don't say that to soccer players. Those athletes have a steady contract, and if they win a championship, then they get a bonus.

"That's how it should be. Not, 'Oh, prove you're going to be a champion.' I'm not going to gamble. It's like gambling. It's a fight -- the best fighter doesn't always win. I've already proven myself as one of the best, and I'm willing to step up when the company needs me. I've proven my value in so many ways."

Gegard Mousasi signed a multifight deal with Bellator MMA and says he is happy with his contract after complaining about his pay toward the end of his pact with UFC. Brandon Magnus/Zuffa LLC/Getty Images

The promotion will also allow him to sign his own in-cage sponsors, which is prohibited in the UFC because of its exclusive apparel deal with Reebok.

One potential downside of moving to Bellator for Mousasi was the loss of a comprehensive drug-testing program, which the UFC provides year-round. The vast majority of Bellator's drug-testing efforts rely on state regulators, and some are better than others.

Mousasi, however, said Bellator president Scott Coker told him he would be willing to address that concern on a case-by-base basis with the fighter.

"That's the great thing about Bellator is that I talked to Scott about all of that," Mousasi said. "I get something to say in Bellator. If I don't trust a guy and want him tested on an unexpected basis, Scott was open to that.

"There is a difference. [The UFC's anti-doping program] was great. My career rocketed after that started. Obviously, I believe guys are using steroids -- but if I believe that, I will have some say in it here."

Mousasi is coming off a somewhat controversial TKO over Chris Weidman in April. The fight was stopped when Mousasi landed several knees to the side of Weidman's head, which were initially ruled illegal. Replays showed the shots were clean, and the fight was waved off.

A pro since 2003, Mousasi is 8-3 since he moved down a weight class in 2014. Although his first opponent has not been determined, he's an instant candidate to face Bellator's 185-pound champion, Rafael Carvalho.

Mousasi is one of several highly ranked fighters to make the move from UFC to Bellator in recent years. That list includes Rory MacDonald, Ryan Bader, Phil Davis, Lorenz Larkin and Benson Henderson.