But six-month figures still reveal turnover up 11% and pre-tax profit up £2.2m to £28.2m.

Consultant Atkins’ performance has been held back by problems with the Metronet consortium, the group’s six-month interim results revealed today.

The group’s results, to 30 September, were impacted by continued delays in the recovery of the capital programme, inconsistent operational performance and restructuring costs, the firm said.

The company also warned that it would take some time to see any signs of recovery: “The recovery of the capital programme and the improvement of the day to day operational performance of the Underground remain crucial to the eventual success and realisation of value from the project.

“While progress has been made over the last six months, it will take some time to evidence any significant recovery. As previously stated, these issues must be satisfactorily addressed if the Group's returns from Metronet are not to be impacted at all levels, including the final value of the investment.”

But the group’s core business performed well, thanks to public increased public spending. Turnover was up by 11% while pre-tax profit rose to £28.2m from £26m. The interim dividend went up by 12.5% to 4.5p per share.

Chief executive Keith Clarke commented: “The results were ahead of our expectations, with most of our core businesses growing strongly in response to public sector demand. Prospects for our business remain good and we are confident that the Group will continue to grow profitably.”

· Atkins announced the disposal of its 25% shareholding in South Manchester Healthcare to Secondary Market Infrastructure for £7.75m, making Atkins a £5.7m profit. Clarke said the sale was in line with the group’s strategy to recycle cash invested in PFI project companies.