Miro Technologies, a San Diego software firm specializing in maintenance and supply management for the aerospace industry, was sold to the Boeing Co. by its owner, Solis Capital Partners, a Newport Beach equity firm, for an undisclosed price.

Miro, formerly a part of Spirent Plc of the United Kingdom, was acquired by Solis in 2004 when it had about 60 employees. Today, the firm has some 120 employees and operations in the U.K., Saudi Arabia and Oman.

Boeing, which was a big customer of Miro, said it acquired the firm to advance the company’s defense logistics support.

The centerpiece of Miro’s services is a software solution Boeing uses for some of its largest logistics contracts, including support for the C-17 Globemaster III and the AH-64D Apache Longbow helicopter. Among Miro’s other customers are the U.K.’s Ministry of Defense, the Royal Saudi Air Force and Oman Ministry of Defense.

Miro is now part of Boeing’s Defense, Space and Security division, one of the world’s largest defense contractors with $32 billion in sales and 61,000 employees worldwide.

Solis said it’s in the process of raising a $100 million investment fund that should close in March.