Germany's largest lender said in March it planned to list the asset management arm, which could achieve a total valuation of around 8 billion euros, within two years as part of a broader overhaul following costly lawsuits and trading scandals.

The requests to pitch for roles such as that of the global coordinator were sent out on Monday, the sources said, adding Deutsche Bank would likely act as the main organiser of the IPO itself but wants help to market the shares.

The bank will start meeting representatives of other investment banks in the coming days to hear their view on the business, which includes its mainstay DWS retail asset management brand, the sources said.

Banks are being asked to specify any concerns over the attractiveness of the business to equity investors, their view on the peer group, valuation method, timing of the deal and potential buyers of the stock.

Banks that helped Deutsche with its 8.5 billion euro capital raising earlier this year stand good chances of securing roles on the deal, people close to the matter have said in the past. They include Barclays, Credit Suisse and Goldman Sachs.

Deutsche Bank declined to comment.

While investors had initially expected the IPO as soon as this autumn, Deutsche Bank pushed it back into the first half of 2018, wanting more time to refine and sell the business's strategy to potential buyers of the stock.

Some investors indicated they would prefer a stronger focus at Deutsche's asset management arm on so-called passive investments or exchange traded funds (ETFs), whereas its main business is currently with actively managed funds.

Deutsche Asset Management currently has 711 billion euros invested worldwide, of which 526 billion are actively managed, 107 billion in ETFs and the rest in alternatives such as real estate.

Deutsche Bank reports third-quarter earnings on Oct. 26.

Division head Nicolas Moreau said in the summer that the bundling of the unit's businesses into one holding company would be done by October, as would the finalisation of distribution and service contracts between the business and its parent.

Deutsche Bank hopes that by giving the unit more operational independence it will attract more talent. Group CEO John Cryan has said the bank will maintain a "controlling and super-majority stake" in the asset management business.

(Additional reporting by Tom Sims; Editing by Maria Sheahan and Mark Potter)

By Arno Schuetze