MILAN (Reuters) - The European Central Bank (ECB) may ask some Italian banks to further boost their capital after a review of their business models later this year, the chief executive of Banca Popolare di Milano (>> Banca Popolare di Milano) said on Tuesday.

Giuseppe Castagna told reporters on the sidelines of a conference in Milan that an ongoing ECB review of banks' riskiness was not causing "much activity" for his bank but added: "It is possible that for some banks this may result in requests for recapitalisation".

He said the ECB had set no deadline but banks expected to hear about the outcome of the review between September and October.

Italian banks fared the worst in a Europe-wide health check of lenders last year, with two - Monte dei Paschi di Siena (>> Banca Monte dei Paschi di Siena SpA) and Carige (>> Banca Carige SpA) - forced to carry out capital increases to strengthen their finances.

Any additional capital requirements for Italian lenders may complicate a wave of merger deals expected this year and next among cooperative banks like Popolare di Milano, following a government reform that obliges them to turn into joint-stock companies within the next 18 months.

Popolare di Milano, which is based in wealthy Lombardy, is regarded as a potential merger candidate for Banco Popolare (>> Banco Popolare Societa Cooperativa), but the latter is also interested in a potential tie-up with UBI (>> UBI Banca Scpa), bankers say.

Another bank looking for merger partners is Banca Popolare dell'Emilia Romagna (>> Banca Popolare dell'Emilia Romagna Sc). CEO Alessandro Vandelli, speaking at the same conference as Castagna, said his lender was interested in M&A deals with lenders that have assets of more than 30 billion euros ($33 billion), so "not small".

(Reporting by Valentina Za and Andrea Mandala; Editing by David Holmes)