Sprint (NYSE: S) Nextel, which already owns the Boost and Virgin Mobile USA (NYSE: VM) brands, maybe mulling whether to buy MetroPCS Communications so that it can dominate the prepaid wireless space.

The idea was floated by Greg Miller, an analyst for Collins Stewart in a note he wrote to investors, reports Bloomberg. He reasoned: “It helps Sprint continue to consolidate its position in the increasingly competitive prepaid marketplace in densely populated major metro centers while allowing MetroPCS shareholders an avenue to continue to participate in the market from a position of greater strength.”

Miller’s theory comes only a week after reports surfaced that Leap Wireless had hired Goldman Sachs to look into selling the company or merging with rivals. In that scenario, MetroPCS was considered a likely candidate. Miller did not address the likelihood of Sprint doing a complete roll-up, where it would buy both MetroPCS and Leap.