The family owners of German shoe chain Reno are seeking to find a buyer for the company by the end of the year, Chief Executive and co-owner Matthias Haendle told Reuters on Tuesday.

Reno owner HR Group is Germany's largest shoe retailer after Deichmann, and has roughly 600 million euros ($672.24 million) in annual sales and staff of 4,500.

"A financial investor would be the logical buyer, but I can also imagine a retailer who partners with an investor," Haendle said in an interview, adding that the group needs fresh capital for investment and acquisitions as it is being squeezed by online groups such as Amazon and Zalando.

The business comprises wholesale unit Hamm, which is doing well, and struggling retail unit Reno, which has 750 outlets, a source familiar with the matter said earlier this year, without providing an estimate on HR Group's prospective enterprise value.

"I cannot imagine that a standalone sale of the two business units would reap more. Together, the two units are more powerful," Haendle said.

Hamm was founded as a leather trading company in 1888, while Reno started in 1977 as a mail-order group. The two merged in 2005 to form HR Group.

Reno's peers include Leiser and Goertz. Buyout groups like Permira, Bridgepoint, Apax and Blackstone have invested in German retail companies in the past, as have distressed-focused groups like Sun Capital or Cerberus.

Former Metro manager Siegfried Kaske owns 50 percent of the business, and the Hamm family and other investors own the rest.

Sellside adviser Rothschild has already received 30 expressions of interest. It expects to send out 90 information packages and hopes to conclude a deal before the end of the year, Haendle said.