The Cobham Composite Products facility off Harbour View Boulevard will shut down this summer after lower-than-expected revenues in the composites business, a company spokesman said Thursday.

Approximately 50 full-time employees at the site were notified Thursday the facility will close, said Greg Alan Caires, vice president for media relations for Cobham. Company officials said when the plant opened that it would produce about 200 jobs.

“The revenue expectations that we had did not materialize,” Caires said by phone after the announcement. “When we made the decision to set up the facility, we expected an expansion of the business base, and it’s not materialized.”

The company will transition its work, which included manufacturing parts for military and commercial airplanes, missiles and munitions, to its larger San Diego, Calif., site, which existed before the Suffolk facility opened in May 2010.

The announcement came as a shock to the city, Economic Development Director Kevin Hughes said.

“It’s definitely a disappointment,” he said. “We worked really close and hard on this deal coming into the city. We were planning on future expansions based on the information we received from them up to last month.”

In December, the city’s Economic Development Authority voted to amend the terms of an investment program agreement with Cobham. The terms of the Investment Fund Program Grant provided to the company indicated it would occupy the building in three phases, with the first already complete and the second and third to complete by January 2013 and January 2016. But the amendment gave them until March 2014 and March 2016, respectively, because of uncertainty surrounding defense spending.

The city has paid $360,000 in incentives to the company so far based on an initial $5 million investment, Hughes said. A repayment provision built into the agreement allows the city to recoup some of the money.

“We’ll be moving forward to recapture about $240,000 of the grant,” Hughes said. The difference of $120,000 equates to what the company has already paid in taxes.

“They were doing some significant things out there,” Hughes said. “We were definitely surprised by this. We’re going to be reaching out to their headquarters to try to better understand what’s going on.”

Caires said employees will be encouraged to seek other positions within the company.

“It’s going to be a couple weeks before we have a more detailed plan regarding exact timing of all the releases,” he said.

Layoffs will begin sometime in the next few weeks, a process that will continue through shutdown, he said. “We will be in a position to let each employee know about their particular status within the next few weeks,” he said.

Caires did not believe the closure is directly related to the 2011 disestablishment of U.S. Joint Forces Command, which had a large facility nearby. JFCOM was not a customer of Cobham, he added.

“It is with genuine regret that Cobham must close this facility, and we sincerely respect and appreciate the contributions our employees have made during the facility’s operation,” a media statement read.