Spanish shipbuilding firm Navantia has placed an order for parts for four diesel-electric subs.
Under the deal, BAE will make eight pressure domes at its base in Barrow-in-Furness, Cumbria, and deliver them to Navantia by the end of 2007.
BAE saw off competition from Germany, France, Russia and the US to win the parts order.
The deal marks the company's first foray into the newbuild export market since 1987 - although BAE has carried out refurbishment work on other submarines.
Source: BBC