The company has asked analysts to meet management in the first half of August and subsequently come up with valuation estimates for the supplier of brakes for trucks and trains, sources close to the matter said on Tuesday.
The analysts' reports will then be used to market the shares to prospective investors.
Owner Heinz Hermann Thiele is expected to officially announce the IPO by mid-September with the listing to take place four weeks later, the people said.
Knorr-Bremse could be valued at around 12 billion euros ($14 bln) in the deal, with roughly a quarter of the shares expected to be sold, the people added.
Knorr-Bremse declined to comment.
Finance chief Ralph Heuwing said earlier this month no new capital would be issued. Instead, Thiele and his daughter Julia Thiele-Schürhoff would reap the proceeds of a sale of existing shares.
For majority-owner Thiele, 77, the IPO is also part of succession planning as he is pushing for professional investors to have a voice in the company's strategy.
According to people close to the matter, Thiele had also been in discussions with peers such as ZF Friedrichshafen, Continental and Bosch in recent months on a potential buyout, but the plans did not gain traction. It was a similar outcome to deliberations to break up the company and merge its rail operations with a peer.
The company has said it expects group sales to increase to between 6.4 and 6.6 billion euros this year and earnings before interest, tax, depreciation and amortization to reach between 1.1 and 1.3 billion euros.
Peers such as Wabco and Wabtec trade at 10 and 18 times expected core earnings respectively, although investors may also look at European high-margin industrials such as Atlas Copco and Assa Abloy when analysing a value for Knorr-Bremse shares.
Knorr-Bremse is working on adjusting its capital structure ahead of the deal, one of the people said.
In 2017, the company agreed to extend its debt issuance programme and paid its owners 850 million euros in dividends.
Knorr-Bremse last year hired Deutsche Bank, JPMorgan and Morgan Stanley to organise the deal and later brought in Unicredit, Commerzbank, UBS and Berenberg to help with the flotation.
Germany has seen a frenzy of listings, including that of Healthineers, Deutsche Bank asset-management arm DWS and online furniture retailer Home24. Some - such as publisher SpringerNature, home-shopping group HSE24 and fashion retailer Takko - failed to make is over the finishing line.
($1 = 0.8533 euros)
(Reporting by Arno Schuetze; Editing by Andreas Cremer/Keith Weir/David Evans)
By Arno Schuetze
