Allied Universal announced the acquisition of Apollo International, a security company whose corporate headquarters is in Walpole, Mass., and has a global office in New York.

With a presence in 30 U.S. states and select global markets, Apollo International provides uniformed security officers, concierge/desk attendant services, investigations, special operations, competitive intelligence, risk management consulting, vulnerability assessments and other security/asset protection programs in many of the same vertical industries that Allied Universal serves. With annual revenues of $88 million and 3,400 employees, the privately-owned entity has been in business since 1990.

Apollo International was recognized this year as the second largest Vietnam veteran-owned Massachusetts company, based on employee count. Crowley and Ryer had served together in Vietnam in 1966 and had committed to a future venture together, a commitment that led to Apollo International 26 years ago.