CHICAGO (AP) — Boeing Co., the world’s second biggest commercial airplane manufacturer, said Wednesday that it earned a better-than-expected $1.2 billion in the first quarter, a 38 percent increase from a year ago as its backlog of orders grew to a record high.

But while the earnings beat Wall Street estimates, its sales missed expectations. Boeing shares rose more than 5 percent in morning trading.

The aerospace company said its profit amounted to $1.62 per share for the quarter ending March 31. That compares with $877 million, or $1.13 per share, a year earlier.

Revenue rose 4 percent to $16 billion from $15.37 billion a year ago.

“We’re off to a good start in what we expect to be another strong year of financial performance for Boeing,” Chairman and Chief Executive Jim McNerney said in a statement.

On average, analysts surveyed by Thomson Financial expected Boeing to earn $1.35 per share on $16.5 billion in revenue.

“Investors (are) apt to like strong (first quarter) and initial … guide for 2009,” Cowen & Co. analyst Cai von Rumohr wrote in a research note Wednesday morning.

The company’s commercial airplane segment saw its operating profits grow 39 percent to $983 million in the January-through-March quarter. Revenue grew 8 percent to $8.2 billion.

Meanwhile, operating profits for Boeing’s defense unit grew 10 percent to $860 million while revenue slipped 2 percent to $7.6 billion.

Boeing said its total backlog reached a new record of $346 billion

The Chicago-based company also reaffirmed its 2008 guidance, saying it expects to earn between $5.70 and $5.85 this year while delivering between 475 and 480 airplanes.

Next year, the company predicted it will earn between $6.80 and $7.00 per share and is on track to deliver between 500 and 505 planes, including 25 of its thrice-delayed 787 jetliner.

The fuel-efficient plane has been beset with delays the company attributed to outside contractors and won’t be delivered to customers until late 2009.

Its bigger rival in commercial aircraft is Europe’s Airbus.

Boeing shares climbed $4.17, or 5.3 percent, to $82.73 in morning trading Wednesday. They have traded in a 52-week range of $71.58 to $107.83.