Leap Wireless International Inc said on Friday it will review MetroPCS Communications Inc's unsolicited offer to buy Leap for about $5.4 billion in stock.

Leap also said Chief Financial Officer Amin Khalifa has resigned to pursue other interests and that Chief Executive Doug Hutcheson will take on Khalifa's duties.

MetroPCS made the made the offer for its smaller rival on Sept. 4 in a bid to fend off competition from larger U.S. mobile service providers. Leap is being advised by Goldman, Sachs & Co and Jeffrey Williams & Co LLC.

MetroPCS offered 2.75 of its shares for each Leap share. Based on Thursday's closing stock prices, that makes the bid worth $77.25 per Leap share, or a 6.6 percent premium over the company's share price before the offer was announced.

Leap shares have risen 15 percent since the bid was announced, even though analysts had long predicted such a transaction.

The combined companies would have a presence in nearly all 200 U.S. markets, but a cumulative 6.2 million subscribers would still be much smaller than the top U.S. mobile providers.

Leap said that Hutcheson had held the CFO job from August 2002 to February 2005, when he was named CEO.