PHILADELPHIA — Falconhead Capital said Thursday it has taken a controlling stake in Rita’s Water Ice Franchise, whose Italian ice treats are sold in 18 states.

The private equity firm did not disclose how much it paid for the stake from an investment group led by Jim Rudolph, who kept a minority position in the company, which is based near Philadelphia.

Falconhead Capital operating partner Thomas Christopoul was named chairman and interim chief executive of Rita’s until a new CEO is named.

David Moross, chairman and CEO of Falconhead Capital, said Rita’s was ripe for likely expansion in the aftermath of the acquisition. Rita’s currently operates mostly in the eastern U.S.