The top shareholder in Monte dei Paschi di Siena , Italy's third biggest lender, said on Monday it had sold a 0.77 percent stake in the bank to boost its own liquidity.

The Monte dei Paschi foundation said the stake - equivalent to 90 million shares - was sold in February 2013 at an average price of 0.2376 euros per share.

Last year, the foundation was forced to cut its stake in the bank to 34.9 percent from 49 percent to pay back creditors.

"Such (stake) sales are exclusively aimed at building an adequate level of liquidity," the foundation said in a statement.

(Reporting By Silvia Aloisi, editing by Stephen Jewkes)