A fast-growing Buffalo-based debt collection agency has acquired a 52-year-old rival Cheektowaga-based agency, creating a combined firm with more than 500 employees and offices in five states and Canada.

Mercantile Adjustment Bureau LLC purchased Creditors Interchange Receivable Management LLC, paying an undisclosed price, according to a news release from Rockville, Md.-based Kaulkin Ginsberg Co., the specialty investment banking firm that represented Creditors Interchange in the deal.

The release did not say what would happen to Creditors Interchange’s employees or operations, but the combined companies would have 500 employees in all. Also, the seller’s former president and CEO, Bruce H. Gray, is now president of Mercantile. In April 2007, Gray tried a sale of Creditors Interchange to publicly traded Debt Resolve, of White Plains, for $60 million in cash and $4 million in stock, but the deal fell through five months later.

“I am very excited to again be working with some of the best in the industry and welcoming them into the Mercantile family,” Gray said in the news release. “The legacy of CI will carry on with Mercantile’s current proven management team and employees combined with CI’s team. Mercantile will have one of the [accounts receivable management] industry’s most seasoned and experienced leadership and employee teams.”

Founded in 1960, Creditors Interchange serves banks, colleges, auto lenders and debt buyers. The agency had as many as 800 employees at one point, including 600 in Western New York in offices on Holtz Drive in Cheektowaga and Hertel Avenue in Buffalo. It also had smaller offices in suburban Cleveland, Philadelphia and Las Vegas, as well as in Fort Lauderdale, Tampa and Jacksonville, Fla. It also had offices in Fort Erie and St. Catharines, Ont., plus a Canadian subsidiary to collect debt in that country and a call center joint venture with an organization in India.

Mercantile provides first-party, third-party and specialty collections services to banks and other financial institutions, debt buyers, colleges and universities, utilities, health care providers and telecommunications companies. The firm has offices in Rochester and Tampa, along with Willow Grove, Pa. The company has been targeting growth through a mixture of acquisitions and gaining more clients, and Creditors Interchange is its second acquisition this year.

Mercantile CEO Jeffrey P. Miller said in a release that the firm is “looking at future acquisition opportunities.”