SAN FRANCISCO, Aug. 16 (Xinhua) -- U.S. top aircraft manufacturer Boeing Company announced Thursday a plan to acquire a California-based firm to grow its space ad satellite business.

Boeing said it is buying Millennium Space Systems, an El Segundo, California-based provider of agile, flight-proven small-satellite solutions, under an acquisition agreement that will expand Boeing's satellite and space portfolio, talent and capabilities.

The privately-owned Millennium Space Systems, which has about 260 employees, develops and manufactures high-performance satellites for exacting missions ranging from 50 kg to more than 6,000 kg.

The small Californian company, with deep expertise in complex systems engineering, worked for NASA on contracts and provided products for the U.S. Air Force.

"Millennium Space Systems' expertise in vertically-integrated small-satellite solutions perfectly complements Boeing's existing satellite portfolio, and will allow us to meet the needs of a diverse customer set," said Leanne Caret, president and CEO of Boeing Defense, Space and Security.

Boeing did not disclose the specific terms of the acquisition, only saying the deal is expected to close by the end of the third quarter in 2018.

After the transaction is completed, Millennium Space Systems, which was founded in 2001, will become a Boeing subsidiary that operates under its current business model.

Media reports said one of Millennium Space Systems' satellites developed for the Air Force is expected to be launched next year.