A New Canaan private equity firm has expanded its portfolio with the acquisition of a manager of facility services for retail and food service customers in the United States, Puerto Rico and Canada.

Gridiron Capital LLC, in partnership with the founder and management team of Wichita, Kan.-based Quality Solutions Inc., acquired QSI for a undisclosed figure.

Through more than 23,000 vendors, QSI provides over 75 trades to more than 9,000 client locations. The company also offers project management and light construction capabilities.

Founded by Eric and Wendy Dunn in 1997, QSI is positioned for significant growth as it meets demand from retail and food service operators who want to outsource complex facility services, freeing them to focus on growth of their core business, according to Gridiron.

"We look forward to working with the QSI team to continue its long history of success, and to expand its services and capabilities for both its customers and vendors," Managing Director Joseph Saldutti Jr. said in prepared comments.

Gridiron learned about QSI by introducing itself to participants in the sector, said Thomas Burger Jr., co-founder of Gridiron and managing partner. Its due diligence included a canvass of QSI customers.

"Their management team is excellent. They are all passionate about customer service. QSI was looking for someone to help accelerate their growth. We like that industry," he said, adding that employees will stay in place.

QSI has a nationwide footprint, but Gridiron sees opportunities to expand its presence, Burger said.

The company has gained a reputation for its project managers taking personal ownership of client service calls, Eric Dunn, chairman and founder of QSI.

"We are partnering with Gridiron because I believe that they share our company's core values and bring with them the operating expertise and financial resources to help QSI reach the next level of success," he said in prepared comments.

Private equity acquisitions are increasing as the debt market comes back, said Soma Biswas, private equity editor for MergerMarket.com.

"Starting this year, the debt markets are pretty strong. U.S. investors look for higher yields that drive demand for speculative debt," she said. "There's a pickup in private equity deals this quarter, compared to the second half of last year."

Private equity firms need debt financing to push through deals and very rarely fund a deal using their own bankroll, said Roger Aguinaldo, chief executive officer and publisher of The Mergers & Acquisitions Advisor.

"I still think there are challenges in financing," he said.

Gridiron's investments are grouped into services, manufacturing and specialty consumer categories.

Besides QSI, its other investments include H.M. Dunn Co., Inc., in Euless, Texas; Apex Engineering International in Wichita; Lakeshore, TolTest Corp., in Detroit; TharpeRobbins in Statesville, N.C.; Executive Cabinetry in Simpsonville, S.C.; Yellowstone Landscape Group in Bunnell, Fla.; Electronic Systems Protection Inc., in Zebulon, N.C.; Ramsey Industries in Tulsa, Okla.; McKenzie Sports Products Inc., in Granit Quarry, N.C.