Private equity investors are lining up bids for German fashion retailer Schustermann & Borenstein in a potential 700-800 million euros ($780-$891 million) deal, sources familiar with the matter said.

Buyout group Ardian has put the business, which has adjusted annual core earnings of 55 million euros, up for sale and has asked for tentative bids by September 12, the sources said.

Private equity groups KKR, Cinven, Permira, EQT and Advent are expected to hand in offers for the business, which may value the company at up to 12-15 times its expected core earnings, they added.

French retail peer SRP Groupe trades at 13 times its expected earnings.

The seller and the potential bidders either declined to comment or were not immediately available for comment.

Schustermann & Borenstein specializes in exporting clothing to eastern Europe and other non-European Union countries. Separately, it sells surplus stock in so-called outlet centers and also in an online community called "Best Secret".

It has annual sales of roughly 300 million euros.

Ardian, which bought Schustermann & Borenstein for about 300 million euros in 2012, is working with JP Morgan on the sale, the people said.

$1 = 0.8977 euros