Boost Mobile founder Peter Adderton said he might buy back the prepaid wireless company if Sprint divests the unit to merge with T-Mobile. But only if the merged company agreed to give Boost a good wholesale deal to sell its service to customers.

"What does that wholesale deal look like?" Adderton said on CNBC's Squawk Alley on Thursday. "In order for Boost to be able to compete, it's got to have a deal that allows it to do that."

The Federal Communications Commission and other regulators "have to police" a deal to allow Boost to compete directly against T-Mobile's MetroPCS and a combined Sprint-T-Mobile, Adderton said. The FCC this week said it would bless a merger between Sprint and T-Mobile after the companies said they were willing to divest Boost Mobile, a mobile virtual network operator that uses Sprint's network and wireless spectrum to offer service to prepaid customers, who are often lower-income.

T-Mobile controls about 41% of the prepaid market through its ownership of MetroPCS, according to estimates from research firm MoffettNathanson. Sprint controls about 17% of the market. Given that level of market control, Adderton has to know that Boost could win as an independent company.