ENGINEERING firm Plexus Holdings saw its share price rise more than 4% on the back of a strong half-year trading update.

The Aberdeen oil and gas industry supplier highlighted a strong forward order book as it posted an 18% rise in pre-tax profit from £1.5 million to £1.7m as sales grew 21% from £9.3m to £11.3m in the six months to December 31, 2012.

The core product at Plexus is called POS GRIP, which is claimed to provide more effective seals between parts in wells and allow drilling to be done more cheaply than using other equipment.

New customer wins in the North Sea include Lotos Exploration and Lundin Norway, while there were additional purchases from Talisman Energy and an extension with Maersk.

Around 41% of Plexus's revenue comes from the UK North Sea, although it is targeting further international growth with subsidiaries in Brunei and Singapore, set up with the intention of expanding sales in the Middle East and Asia.

In addition to its Scottish headquarters, Plexus already has other sites in London, Cairo, Kuala Lumpur and Houston, Texas.

Chief executive Ben Van Bilderbeek said: "We have continued to make substantial progress in organic sales growth, as well as in relation to a number of strategic initiatives targeting future opportunities.

Gross margins grew from 70.1% to 70.7%, which was attributed to greater activity levels in the rental of some high pressure and high temperature equipment.

A joint industry project to develop a new POS GRIP subsea wellhead has attracted partners including Total, Maersk, Shell and Tullow Oil.

Physical testing of the different parts of the system is expected to begin in the near future.

Plexus signalled that it expects to benefit from the Patent Box tax reliefs coming into effect from next month, with a significant element of its profits potentially qualifying for a reduced corporation tax rate.

As a result of the trading performance Plexus increased its interim dividend 12.8% to 0.44 pence per share.

The shares ended the day up 9.5p, or 4.4%, at 224.5p.