Goldman Sachs is majority shareholder of the Highstreet property consortium, reported the weekly Bild am Sonntag newspaper at the weekend.
Highstreet owns the properties in which 86 of the 120 Karstadt stores are housed, but has not until now shown interest in running the shops themselves.
But Bild am Sonntag said Highstreet would make an offer to Karstadt insolvency administrator Klaus Hubert Görg this week – just days ahead of the Friday deadline for bids.
Highstreet would reportedly be the favourite bidder, and has already held secret talks with the Verdi trade union which represents shop-workers.
There would be no extensive job cuts should the deal come off, the paper reports, although the working week would be extended from 37.5 to 39.5 hours with no extra pay.
The giant Metro group, which owns Media Markt, Saturn and Galeria Kaufhof, is still in the running to buy out Karstadt, with CEO Eckhard Cordes recently writing to Görg to signal his continued interest.
The Metro concept would not guarantee to keep all the Karstadt shops running, rather incorporating them into its current department store chain.