* Bank reviewing asset sales to boost capital
* 10 potential bidders contacted for Pioneer-source
* Bank mulling large-size sale of bad loans-sources
By Gianluca Semeraro and Paola Arosio
MILAN, Sept 7 (Reuters) - Italy's largest bank UniCredit CRDI.MI is seeking a strategic partner for its asset management business Pioneer, as part of a plan to bolster its capital base, several sources close to the matter said on Wednesday.
UniCredit in July ended long-running negotiations to merge Pioneer with Santander's asset management division in a deal valuing Pioneer at 2.75 billion euros ($3.1 billion) because of regulatory hurdles.
The Italian bank said then it was looking at alternative options for Pioneer, including a market listing. Executive Jean-Pierre Mustier, appointed in July, is widely expected to launch a multi-billion euro capital increase and sell assets in coming months to boost UniCredit's balance sheet.
He is conducting a wide-ranging review of the bank's operations, with an announcement expected by the end of the year.
One of the sources said on Wednesday the bank had contacted around 10 potential partners for Pioneer, without elaborating. A second source said the bank favoured an industrial partner with experience on asset gathering, rather than a private equity fund.
UniCredit declined to comment.
Il Messaggero newspaper reported on Wednesday that non-binding offers for Pioneer were expected on Sept. 20 and that among the potential bidders contacted were Credit Agricole's CAGR.PA asset manager Amundi AMUN.PA , BNP Paribas BNPP.PA , Italian insurer Generali GASI.MI , French insurer Axa AXAF.PA , U.S.-based firms Invesco IVZ.N and Blackstone (NYSE:BX) BX.N .
Amundi, BNP, Generali, Axa and Invesco declined to comment, while Blackstone was not immediately available for comment.
UniCredit is also in talks to sell its remaining stake in Polish bank Pekao PEO.WA and could also sell its online broker FinecoBank FBK.MI , sources have said. Upon his arrival, Mustier sold 10 percent stakes in both units, raising 1 billion euros.
The sources also said UniCredit was mulling a large-size sale of non-performing loans with 4-5 potential buyers interested.
($1 = 0.8902 euros) (Writing by Silvia Aloisi; Editing by Mark Potter)