Private equity owner MBB
MBB and the banks declined to comment.
Analysts at brokerage Equits said in a note last year that Aumann could be valued at 300 million euros ($320.49 million)including debt or 1.5 times Aumann's estimated 2017 sales in a potential IPO.
MBB could reap more than 130 million euros in proceeds from the Aumann stock market listing, increasing MBB's fire power for acquisitions to 200 million euros, Equits said.
According to analysts at Hauck & Aufhaeuser, Aumann could even be valued at 460 million euros.
($1 = 0.9361 euros)
(Reporting by Arno Schuetze and Alexander Hübner; Editing by Harro ten Wolde)