Profit before tax jumped 18% to £31.1m in the six months to 30 September, compared with the same period in 2005. Revenue for the company increased 17% to £605.5m.

Atkins said a strong rail business in the Middle East contributed to the success. The group said it has also won significant signalling contracts in the UK.

However, Atkins suffered financial penalties and extra costs from its involvement in the underperforming Metronet. Atkins has 750 people working on the project.

The group said: "The stations modernisation programme remains a cause for concern with only two further stations being completed and accepted back into service over the past six months. This has continued to impact the group's profitability."