The deal adds two partners and 13 staffers to Mann Frankfort's roster, giving it 20 partners and about 200 staffers.

Mattison and Riquelmy has a long history in the profession, tracing its origins to the 1920s.

"We've known each other for years, and there's a strong mutual respect. They're a high quality firm,'' Mattison partner Albert Krafcheck said. "We started talking about a merger last year as a possible fit. We both are interested in mid-market, high-income and high-net worth business.''

Mattison and Riquelmy currently has a client base of about 1,000, many of them in food distribution, automotive business, 501(c) non-profit income tax consultations, the timber industry and land development business. But 20 to 30 percent of Mattison and Riquelmy's clients are energy-related.

Mann Frankfort is looking for more mergers. Mike Richter, shareholder and a member of Mann Frankfort Stein & Lipp's management committee, said, "We are always looking to acquire well-established quality companies with experienced personnel."

Rick Stein, shareholder and a member of the Mann Frankfort management committee, added, "We will continue to look for opportunities with other CPA firms.''