A unit of Germany's MAN AG reportedly confirmed to a major news agency that it would buy a 15 percent stake in Howaldtswerke- Deutsche Werft (HDW) by October 1.
The move follows a surprise takeover of the shipyard by U.S.-based One Equity Partners last month who freed the yard from the control of ailing engineering firm Babcock Borsig.
The head of MAN unit Ferrostaal AG, reportedly told a news conference that the firm agreed to buy a 15 percent stake offered by One Equity soon after it gained control of 75 percent of HDW's shares.
HDW is the world's leading producer of non-nuclear submarines. One Equity said it bought the controlling stake as a financial investment.
The MAN official reportedly said the stake in HDW was an attractive way for Ferrostaal, MAN's industrial services unit, to secure its continuing business with HDW.