Ridgemont Equity Partners has agreed to buy logistics company Worldwide Express from Quad-C Management. The PE firm will merge the target with portfolio company Unishippers Global Logistics and the combined company will be called Worldwide Express Global Express. Financial terms were not disclosed.

Worldwide Express, based in Dallas, provides shipping along with truck and air freight services. Quad-C invested in the company in 2013. Unishippers, located in Salt Lake City, Utah, is also a shipping logistics company and was acquired by Ridgemont in 2015. Current Worldwide Express CEO Tom Madine will lead the combined business, which will have 308 U.S. offices and more than 90,000 customers.

Quad-C, based in Charlottesville, Virginia, invests between $75 million to $400 million companies in the business services, consumer, industrials, healthcare, distribution and logistics sectors. In 2016, the PE firm bought Stanton Carpet Corp. from Norwest Equity Partners.

Ridgemont is a Charlotte, North Carolina private equity firm that typically invests between $25 million to $100 million in companies that have up to $30 million in Ebitda. In 2016, Ridgemont portfolio company the Cook & Boardman Group purchased Delta Door and Hardware LLC.

Logistics companies have become attractive targets as the e-commerce market continues to grow. Atlas Air Worldwide Holdings Inc. (Nasdaq: AAWW) bought air cargo provider Southern Air Holdings Inc.; Graycliff Partners invested in “last mile” logistics provider Installs Inc.; and Nascent Technology LLC purchased cloud-based supply chain management company Smart Track Logistics Inc.

Fidus Partners, Harris Williams & Co. and White & Case LLP are advising Quad-C and Worldwide Express. Piper Jaffray & Co. (NYSE: PJC) is advising Unishippers. Kirkland & Ellis LLP is representing Ridgemont. Antares Capital, Deutsche Bank and Citizens Financial Group are providing financing.