* Monte Paschi foundation stake falls to around 12 pct
* Bank chairman expects BlackRock to subscribe cash call
* Foundation confirms inspection by Consob, financial police (Adds details, BlackRock comments, context)
MILAN, March 26 (Reuters) - The main investor in Banca Monte dei Paschi di Siena sold another 3 percent stake in Italy's third-largest lender ahead of a 3 billion euro ($4.14 billion) capital increase the bank needs to avert nationalisation.
The Monte dei Paschi foundation, a not-for-profit entity, sold 358.5 million shares between March 19-24 worth a total of 85.7 million euros ($118 million), a share transaction filing showed on Wednesday.
The foundation said on March 18 that it held a 15.07 percent stake in Monte Paschi after halving its stake earlier in March in a move that allowed it to pay of all of its debt. It also cleared the way for the bank's rights issue the foundation had delayed while it found a buyer for its shares.
With the latest sale the foundation's stake in the bank falls to around 12 percent.
The foundation declined to comment on the stake sale.
Monte dei Paschi, the world's oldest bank still in business, was bailed out by the state with 4.1 billion euros of aid last year after being hit by the sovereign debt crisis and a derivatives scandal.
It needs to carry out the capital increase to pay back most of the state aid as part of a tough restructuring demanded by the European Commission, or else would face nationalisation.
Monte Paschi Chairman Alessandro Profumo said earlier on Wednesday he hoped the foundation would remain a shareholder.
Antonella Mansi, the foundation's head, has said the politically connected body hoped to keep a small stake in the bank after the cash call and was still on the lookout for a strategic partner for part of the holding still in its hands.
Analysts have said the foundation's share sales were turning the bank into a potential takeover target given its now more fragmented ownership structure.
Profumo added that he expected the bank's new investor BlackRock to subscribe to part of the capital increase, which he expected to be launched in the second half of May.
The asset management company has acquired 5.748 percent of Monte Paschi, a holding that makes it the second-largest investor in the Tuscan bank, a regulatory filing showed last week.
"By definition, those who buy (a stake) today know that there will be a capital increase," Profumo told journalists on the sidelines of an event in Siena. "Those who bought will certainly subscribe to the capital increase."
BlackRock could not immediately be reached for comment.
Profumo added that BlackRock's investments in Monte Paschi and in other Italian banks were a sign that Italy was again attracting investor interest.
In the past month, BlackRock became top investor in UniCredit, Italy's biggest bank by assets, and in Intesa Sanpaolo, its largest retail bank.
"This sends two important signals: Italy is regaining interest of major players and Monte Paschi is seen as a bank that, as they say, has done its homework," Profumo added.
This sentiment was shared separately on Wednesday by the chairman of Intesa Sanpaolo's supervisory board. "It is an absolutely positive signal and I have heard nothing but positive comments from our shareholders," Giovanni Bazoli said.
In a separate statement, the Monte Paschi foundation confirmed reports of an inspection on Wednesday by market regulator Consob and the financial police.
The operation was related to the foundation's sale of a portion of its stake in the bank earlier this month, it said, adding that it was fully cooperating with the authorities. ($1 = 0.7254 Euros) (Reporting by Agnieszka Flak, Gianluca Semararo, Silvia Aloisi in Milan, Stefano Bernabei in Rome and Silvia Ognibene in Siena; Editing by Robin Pomeroy and Cynthia Osterman)