Aberdeen-based Plexus said Maersk has agreed to exercise two one-year extension options attached to an original contract to supply wellhead technology and associated services for an exploration programme in the North Sea.
The initial contract was announced in December 2009 with an estimated value of £3m. Plexus said the contract will now run to the end of 2014, subject to finalisation.
The company has won a series of deals involving companies like Lundin, Talisman Energy and Shell in recent months.
Chief executive Ben Van Bilderbeek won Entrepreneur of the Year at the recent Quoted Company Awards.