CVC, Bridgepoint and a consortium of Advent and Bain are expected to hand in an offer for the group, which is jointly-held by several German banks, by a deadline early next week, the people said, adding strategic players such as Wirecard (>> Wirecard AG) had dropped out of the race.

Concardis' largest shareholder is Deutsche Bank (>> Deutsche Bank AG), with a 16 percent stake, while smaller stakes are held by Commerzbank (>> Commerzbank AG), Unicredit (>> UniCredit SpA), as well as savings banks and cooperative banks. They are expected to decide on a buyer early next year.

Concardis offers card payment terminals as well as payment technology for e-commerce groups and is viewed as a non-core business by many of its owners.

The company is hoping a new owner will invest in new technologies and an expansion of its so far very Germany-focused footprint.

Concardis posted core earnings of 33.9 million euros and a net profit of 24.2 million euros on sales of 480 million euros last year. It said in its annual report that core earnings were expected to rise 7 percent this year.

Private equity groups have shown with investments in Worldpay (>> Worldpay Group PLC), Nets (>> Nets A/S) and ICBPI that they are able to develop and strengthen payments groups.

More deals in the sector are likely to follow. In Germany, small peer Heidelberger Payment (Heidelpay) is currently also up for sale, while savings-banks owned B+S Card Service is looking for an investor.

Concardis and the bidders declined to comment.

(Reporting by Alexander Hübner, Dasha Afanasieva and Arno Schuetze; Editing by Tina Bellon and Mark Potter)