If there is an equivalent to the “skunk works” for Lockheed’s secret warplane development lab in RTP, it’s the three research development labs at MCNC.

They finally belong to RTI international.

RTI and MCNC said Monday that they had wrapped up the sale of the units to RTI that were announced last fall. The deal is valued at over $5 million, with the money being spread out over four years, according to RTI. Some 61 employees are involved.

The development labs at MCNC work for a variety of clients, including the federal government and defense department. Many of the projects are very high-tech — and secretive — in nature.

“If I tell you what all they do,” MCNC’s chief executive Dave Rizzo likes to say, “I would have to shoot you.”

Now part of RTI are MCNC’s Signal Electronics Division, Materials and Electronic Technologies Division and Advanced Network Research Division. All were part of the MCNC Research development Institute group.

The MCNC divisions become part of RTI’s Science and Engineering Group and will operate at existing MCNC facilities for “at least the next three years” under a lease agreement, RTI said.

The acquisition is part of an effort by RTI to expand its efforts in science and technology research and development.

“Adding these talented researchers and their facilities to RTI’s Science and Engineering Group will allow us to pursue a number of opportunities in new research areas and technologies,” said Victoria Haynes, president of RTI, in a statement. “The synergy between our research activities will no doubt create many new exciting possibilities, and RTI has the business systems, infrastructure and other resources needed to ensure the success of these high-technology research lines.”

MCNC still operates its grid computing and networking services group as well as its venture capital and economic development foundation.

RTI: www.www.rti.org

MCNC: www.mcnc.org