Leap Wireless International Inc., which offers low-cost, prepaid wireless service, posted a larger fourth-quarter net loss Thursday as expenses grew.

The company posted a net loss of $61.9 million, or 82 cents per share compared with a loss of $55.6 million, or 82 cents per share, in the same period a year earlier. Leap had more outstanding shares in the latest quarter, which lowers per-share results.

Revenue rose 16 percent to $599.3 million from $518.9 million.

Analysts, on average, were expecting a loss of 65 cents per share on revenue of $633.7 million, according to a poll by Thomson Reuters.

The quarter's operating costs rose 15 percent to $593 million.

Leap added about 298,000 net customers during the quarter, bringing its total customers to nearly 5 million at the end of the period.

For the full year, the company posted a loss of $239.5 million, or $3.30 per share, compared with a loss of $150.2 million, or $2.21 per share, in the previous year.

Revenue rose 22 percent to $2.38 billion.

Doug Hutcheson, the company's president and CEO, said Leap expects its churn, or customer turnover rate, to remain "higher than historical levels" over the short term.

But, he added, the company is looking forward to "improved performance over the long-term due to expected improvements in customer tenure in our newly launched markets, potential lower unemployment levels among our customer base and the impact of new enhancements we are introducing." These include an expanded calling footprint and the launch of a BlackBerry device and an Android phone later in the year, the company said.

Shares fell 19 cents to $14.60 in after-hours trading. The stock had closed up 19 cents at $14.79.