A Bankia representative declined to comment. The FROB bailout fund was not immediately available for comment.

Confirming a report published on Monday by Spanish online news outlet Vozpopuli, the source said the sale, worth around 840 million euros ($944 million), would be via an accelerated bookbuild.

Economy Minister Luis de Guindos said last month that the government, which owns 67 percent of Bankia, was planning to further sell stakes "as soon as possible".

($1 = 0.8477 euros)

(Reporting by Carlos Ruano; Writing by Angus Berwick; Editing by Susan Fenton)

Stocks treated in this article : Morgan Stanley, UBS Group, Bankia SA