NORTHERN Rail parent company Serco has said a bulging order book is helping to underpin its continued growth after revealing an increase in profits last year by 18 per cent to £136.1m.

The international services group, which operates Northern Rail with its partner NedRailways, also saw overall revenues grow by 11.1 per cent to £3.2bn.

Serco, which was announcing its preliminary results for 2008, said it had identified increasing growth prospects, even in the “current challenging economic environment”.

The firm, again in partnership with NedRailways, is one of four bidders shortlisted for the contract to run the Tyne and Wear Metro.

A spokesman said: “We are looking forward to the opportunity of bringing the very best skills from across our businesses to the development of the highest quality solution for the passengers of the Metro, and delivering the step change in service and quality that Nexus is seeking for this important transport system.”

Serco, which has an order book worth £16.3bn, also won the contract to operate the Dubai Metro from September last year and made significant acquisitions in the US and India. It is also the sole operator of the Docklands Light Railway, in London.

Referring to Northern Rail, it said the number of passengers travelling with the rail company had risen by 31 per cent in four years to 83.3m.

Northern, which has 4,500 staff, operates several rail routes in the region, including Bishop Auckland-Darlington- Middlesbrough-Saltburn, east Cleveland.

In the North-East, Serco also runs the International Fire Training Centre on Teesside, where expert aviation fire-fighting training is provided to more than 70 countries Internationally Serco, which has 55,000 staff, delivers services in the US, Australia, India and the Middle East, as well as the UK.

Christopher Hyman, chief executive of Serco Group plc, said: “In 2008, we delivered strong operational and financial performance.

“We continued to grow our existing business and further strengthened our capabilities in existing and new markets.

“While the global economic environment seems likely to remain challenging, we have a substantial order book that gives us high visibility on our future revenues, together with increasing growth prospects.”