One Equity Partners, the private equity arm of US-based Bank One, has taken a stake in Germany's Howaldtswerke-Deutsche Werft (HDW), a manufacturer of conventional submarines.

One Equity is following in the footsteps of the Carlyle Group, which has long shown its affinity for defence industry acquisitions. It is looking to be an increasingly prescient strategy given the US administration's hawkish ambitions in its global war against terrorism.