Italy's state-controlled defence and aerospace group Leonardo on Wednesday said it would sell a 6.3% minority stake in its U.S. subsidiary Leonardo DRS on the market.

The 16.5 million shares in Leonardo DRS making up the stake are worth about $344.2 million, according to Reuters calculations based on their closing price on Wednesday.

Proceeds from the sale will be used to increase financial flexibility to finance possible investments and acquisitions, Leonard said in its statement announcing the sale.

Index provider MSCI on Tuesday added Milan-listed Leonardo to its widely-followed MSCI ACWI stock index.

Last week, Leonardo posted rising core earnings, revenues and new orders and confirmed its full-year guidance. Profitability in the nine months to Sept. 30 was mainly supported by European electronics, aircraft and helicopters.

Morgan Stanley, BofA Securities and J.P. Morgan are acting as joint book-running managers for the proposed share offering.

(Reporting by Urvi Dugar in Bengaluru; Editing by Tom Hogue)