William Blair Advises Spectrum Control

William Blair acted as financial advisor to Spectrum Control, a portfolio company of AEA Investors (AEA), in connection with its pending sale to Greenbriar Equity Group. The transaction signed on September 18, 2026.

About the Companies

Spectrum Control is a U.S. based provider of mission-critical RF and microwave components, including filters, interconnects, and signal conversion modules that bridge the analog and digital domains. Spectrum Control's products are designed into defense, space, and specialty end-markets, embedded as a preferred source across 200-plus defense programs.

Founded in 1968 by the Rockefeller, Mellon, and Harriman family interests and S.G. Warburg & Co., AEA is a leading global alternative investment firm that has partnered with middle-market businesses for over 55 years. With approximately $19 billion in assets under management, AEA invests across private equity and private credit strategies through a global network of investors, operators, and advisors.

Founded in 1999, Greenbriar Equity Group is a private equity firm based in Greenwich, Connecticut focused on market-leading advanced manufacturing, supply chain, and business services companies. With $17 billion of committed capital raised across its funds, Greenbriar Equity Group has invested in sectors including aerospace and defense, logistics, aviation, and other highly regulated industries.

Learn more about our aerospace, defense, and government services investment banking expertise.