* Shares end down 2.8 pct after volatile session (Adds comments, background, share activity)MILAN, Oct 13 (Reuters) - Two contenders for Banca Popolare di Milano (PMII.MI) stepped up their campaigns on Thursday to take charge of the Italian bank and curb the power of the bank’s employee-shareholders.One of the contenders, which is allied with the bank’s powerful Amici di Bipiemme association of employee shareholders, said the association favours keeping managing director Enzo Chiesa in the management of the bank.The Amici, or “friends of BPM,” hold about 4 percent of the cooperative bank’s capital, but BPM’s one-head-one-vote system in shareholder meetings gives the association strong influence over the bank’s top management and strategy.BPM is overhauling its governance at the behest of the Bank of Italy and creating a dual-board system with a supervisory board representing its owners and a management board with powers to run the bank’s operations.Ahead of a planned 800 million euro capital increase, two competing funds are vying to take control of BPM under the revamped governance and are campaigning in the bank’s branches across Italy to win over employee shareholders.On Thursday, one candidate for supervisory board chairman Filippo Annunziata gave details on the campaign waged by his slate of director nominees which is allied with the private equity fund InvestIndustrial.InvestIndustrial has a 2.7 percent stake in BPM. A source close to the matter has said it was considering going to 9.9 percent. [ID:nL5E7L40TO]In a conference call with reporters, Annunziata said he favoured InvestIndustrial chief Andrea Bonomi and his representatives joining the bank’s planned management board.”My slate has believed in singling out Chiesa as the person to be in charge of the future management of the bank,” Annunziata said, referring to BPM’s managing director.The second fund trying to win over support for a turnaround of BPM is Italian banker Matteo Arpe and his Sator fund.Arpe is known for his turnaround of the Rome bank Capitalia, which was subsequently taken over by Italy’s largest bank UniCredit (CRDI.MI).On Thursday, Arpe said on the sidelines of a presentation that neither he nor Sator has any shares in BPM.The presentation was of a list of candidates for the BPM supervisory board headed by Marcello Messori, which has support of the Fabi and Fiba/Cisl trade unions.BPM shares closed down 2.8 percent after rising by more than 4 percent during the session on the prospect of Arpe taking over the management.($1 = 0.730 Euros)