(Adds source, detail)
MILAN, May 20 (Reuters) - The top shareholder in Banca Carige said on Tuesday it had started to place a stake of around 15 percent in the Italian mid-sized bank, cutting its holding ahead of a planned rights issue next month.
The banking foundation that owns more than 40 percent of the Genoa-based lender has no money to invest in Carige's upcoming 800 million euro cash call. It has received the green light from regulators to cut its stake to 19 percent.
A market source said the foundation would place the shares at a price of between 0.48 euros and 0.435 euros each. That would represent a discount of between 4.4 percent and 13.3 percent to Tuesday's closing share price.
Shares in Carige closed down 1.18 percent on Tuesday at 0.502 euros.
"The operation starts immediately and the Fondazione Carige reserves the right to close it at any time," the not-for-profit foundation said in a statement.
Banca IMI and Credit Suisse Securities are joint-bookrunners of the offer, which is reserved for institutional investors. (Reporting by Valentina Za and Elisa Anzolin; Editing by Pravin Char)