It wasn’t enough for Allied Universal to make one huge deal last August. Since then, it has gobbled up five more companies with at least $398 million in sales and about 12,000 employees.

AlliedBarton Security Services and Universal Services of America agreed to create a firm with 150,000 employees, the largest security services company in North America.

The company will maintain headquarters in both Santa Ana and Conshohocken, Pa. and projects it will reach $4.5 billion in annual sales.

For now, the doubling of 2016 sales pushed the company’s revenue to $3.4 billion, good for a No. 6 ranking, up seven spots, on the Business Journal’s list of the biggest private companies in Orange County. However, it cut its OC employee count in half to 4,017.

Universal is backed by Warburg Pincus, while AlliedBarton was owned by France-based Wendel Group.

Warburg Pincus and Wendel are lead investors with equal voting rights and board representation. Members of management will also have ownership interests in the combined company. Steve Jones, who was chief executive of Universal Services, is leading the new company. The majority of the integration was expected to be completed by the end of the first quarter.

Among its acquisitions in the past year:

• In May, it bought Alert Protective Services, a residential community security firm based in Sarasota, Fla. Alert, which was founded in 2005, had $10 million in annual sales and 430 employees.

• In February, it acquired the security services portion of Yale Enforcement Services Inc., a Belleville, Ill.-based company. Yale Enforcement’s 1,800-plus employees work in healthcare, manufacturing and warehouses throughout the Central, Midwestern and Southern states.

• In November, it bought Source Security & Investigations, based in Halifax, Nova Scotia, to expand in Canada. Founded in 2002, Source Security provides uniformed security professionals and technological security in eight provinces and 21 cities in Canada.

• In October, Allied purchased FJC Security Services, based in Floral Park, N.Y. FJC provides both uniformed security professionals and a leadership team with background in law enforcement and military. It has a staff of 6,300 and annual sales of $300 million.

• In September, it acquired Apollo International, based in Walpole, Mass. Apollo. Founded in 1990, it has annual sales of $88 million and 3,400 employees in 30 U.S. states.