Leap Wireless International Inc. said on Sunday its board of directors had unanimously rejected an unsolicited bid worth more than $5 billion from larger rival MetroPCS Communications Inc.

After a review of the all-stock bid, Leap said in a statement the deal was not in the best interests of the company and its shareholders.

MetroPCS had bid 2.75 of its shares for each Leap share, or $69.03 per share based on Friday's closing price, according to Leap.

In a letter to MetroPCS Chairman and Chief Executive Roger Linquist included in the statement, Leap said the bid was too low because it did not reflect the company's strong growth prospects and said Leap was better positioned than MetroPCS within the industry.

Your proposal fails to take into account Leap's robust growth prospects, Leap President and Chief Executive S. Douglas Hutcheson said in the letter.

In a statement issued on Sunday, MetroPCS said: We are disappointed, unimpressed and studying our options.

Leap's shares had slipped about 11 percent since September 4, when the bid was announced to Friday's close at $74.37 per share.

Analysts had said the offer was valued at 8.5 time Leap's estimated earnings before interest, tax, depreciation and amortization -- lagging behind the nine times EBITDA multiple of other recent deals.

MetroPCS' widely anticipated bid to buy Leap was seen as a move to fend off competition from larger U.S. mobile service providers, which are encroaching on MetroPCS and Leap's strategy of offering customers unlimited calls for a flat rate.

A combination of the two wireless companies would have created a provider with a presence in nearly all 200 U.S. markets, but its cumulative 6.2 million subscribers would still be far fewer than that those of the top U.S. mobile players.

Leap was advised by Goldman, Sachs & Co and Jeffrey Williams & Co LLC.

(Reporting by Matt Daily)