Cort Business Services, the Chantilly-based supplier of furniture and fixtures, is quietly testing the waters of the party rental business.

The company, which has $420 million in annual revenue and oversees the nation’s largest trade show and events business, scooped up AA Party Rentals, a firm based in Mountlake Terrace, Wash., on Thursday as part of its latest bid to broaden its events business in the Seattle area. Terms of the deal were not disclosed.

“We’re looking to marry the party business with our event and trade show business,” said Jeff Pederson, president and chief executive of Cort. “Our business is tied quite closely to the economy.”

Cort, which was founded in 1972, provides rental furniture for homes, businesses and events, as well as relocation services.

The company’s trade show and furniture rental businesses, which rely heavily on corporate budgets, have been relatively flat in recent years, Pederson said. Party and event rentals, meanwhile, have rebounded since the recession. “The events business has been a very solid growth business,” he said.

The firm — a subsidiary of Warren Buffet’s holding company, Berkshire Hathaway — first dipped its toes in the party rental business with a 2011 acquisition of ABC Special Event Rentals in the Seattle area. That purchase, combined with the most recent acquisition, is projected to add about $12 million in annual sales to the company’s bottom line.

“We’re moving into tenting and linens — the typical things you think of when you attend a large gala or wedding,” Pederson said.“It remains to be seen if we decide to do this in other places around the country, but certainly that is something we’re looking at.”

Capital Business is The Post’s weekly publication focusing on the region’s business community.