SUBSEA 7, which employs 2000 people in Scotland, said it has won almost $1 billion (£650m) worth of business in the North Sea this year amid booming investment in the area.

The oil services firm has won a string of bumper contracts to work on new fields that oil and gas firms plan to bring onstream in the North Sea to meet strong demand for energy.

With a big presence in Aberdeen, Subsea 7 has been capitalising on the efforts of some overseas oil and gas firms to maximise production on the acreage they have acquired in the North Sea. This is resulting in a surge in spending on the kind of services Subsea 7 provides like laying pipelines on the seabed and installing risers linking wells to the surface.

The business wins in the first six months of the year include a $300m contract to provide services for the flagship "Western isles" scheme planned by Korean-owned Dana Petroleum.

This will involve bringing two fields east of Shetland into production using subsea wells connected to a floating production vessel.

Subsea 7 will provide underwater construction services for the redevelopment of the Montrose area fields by a venture owned by Talisman of Canada and China's Sinopec under a $285m contract.

When contract wins in the Norwegian sector are included, Subsea 7 clinched North Sea deals worth $745m in the six months to June.

The contract successes helped Subsea 7 amass a record order backlog worth $10.4bn at June 30, up from $8.3bn at June 30 in 2012.

Some 41% of the backlog has been won by the North Sea and Canada division.

Subsea 7 chief executive Jean Cahuzac said: "Tendering levels remain strong in the North and Norwegian Seas."

Since June 30, the firm has won a $170m order from Norway's Statoil for work related to the development of the Mariner heavy oil field west of Shetland.

The success of the firm provides further evidence of how strong investment by oil and gas firms in the North Sea is boosting activity and employment across the supply chain in Scotland.

Subsea 7 employs 1800 people in Aberdeen and Wick. The company said it has now built 71 bundles of pipelines at its specialist fabrication facility in Wick. It has an extra 120 staff at a pipeline engineering centre in Glasgow.

The wins also underline the depth of expertise in the lucrative area of subsea engineering in Scotland. With firms taking the search for oil and gas into ever deeper waters global investment in subsea facilities is expected to remain strong for years.

Helped by contract wins in previous periods, Subsea 7 lifted operating profits in its North Sea and Canada division by 30% in the six months to June, to $221m from $171m in the same period in 2012.

However, group profits were dented as a result of the challenges the company has experienced in Brazil, another area in which activity is booming.

Subsea 7 provided for a further $300m losses on work on a $1bn contract with Petrobras for work on the development of the Guara and Lula discoveries off the country. It said progress is being hampered by challenging weather conditions in the Santos basin.

Registered in Luxembourg, with headquarters in London, Subsea 7 saw earnings before interest, tax, depreciation and amortisation of $380m in the first half, up from $551m last time.

Group revenues increased to $3.1bn from $2.9bn.

The group was formed through the merger of the Acergy and Subsea 7 businesses in 2011.