PLEXUS Holdings, the Scottish oil and gas engineering specialist, grew profits by one-third in the first half of its financial year when the company won a wider following for its wellhead technology.

Aberdeen-based Plexus made £1.46 million pre-tax profit in the six months to December compared with £1.1m in the same period in 2010.

The company increased turnover by 24%, to £9.3m, from £7.5m.

Plexus won a series of contracts from inter-national oil and gas firms that want to use its POS GRIP technology to drill wells. These included the first orders for use in Malaysia and Russia.

Plexus claims POS GRIP allows firms to produce more effective seals between the parts in wells and to drill them more cheaply than when using other techniques.

The North Sea is a core market.

The company also won an apparent vote of confidence from a group of prominent oil and gas firms, including Shell and Tullow. These are acting as consulting partners in a project in which Plexus aims to develop a version of POS GRIP that could be used on wells that lie on the seabed as well as those that are on rigs.

Plexus chief executive Ben Van Bilderbeek said such a system could allow oil and gas firms to monitor what is happening inside subsea wells and to intervene remotely.

The directors believe Plexus will be a beneficiary of the changes in engineering methods which are expected to follow moves by oil and gas firms to explore at increasing depths and in high pressure and hot environments.

Signalling confidence, the directors approved a 11.4% increase in the interim dividend to 0.39p per share from 0.35p per share last time.

Plexus recently recruited three more skilled engineers to cope with the increased workload. It employs around 100 people in Aberdeen, compared with 22 when it floated on the AIM market in 2005.

Shares in Plexus Holdings closed up 3.5p at 121p.