Barclays, Santander, Societe Generale and Stifel have joined BofA, Citi, Credit Suisse and Mediobanca in the consortium, MPS said.

MPS said in June it had struck a preliminary agreement with a group of banks to pick up any unsold shares in the cash call, adding the signing of the actual underwriting contract was subject to a number of conditions, including positive feedback from investors.

MPS needs private investors to contribute 900 million euros to its capital raising to avoid breaking European Union laws on state aid to banks, but volatile markets and political instability in Italy complicate its efforts.($1 = 0.9771 euros)

(Reporting by Valentina Za)