BUS and rail group Go-Ahead's South Central franchise was the driving force behind a 56 per cent surge in underlying half-year profits.

The addition of the London commuter service 15 months ago helped turnover rise 24 per cent to £537.7m and profits reach £33m before one-off items.

Go-Ahead, which also runs the Thameslink and Thames Trains franchises, said operating profits from the rail division in the six months to December 28 rose to £14.6m from £4.8m a year earlier.

However, the company said growth rates had not recovered to the levels on the network before the Hatfield crash and subsequent rail repairs.

Go-Ahead operates the South Central service formerly run by Connex as a joint venture. It said it was close to securing a seven-year franchise with the Strategic Rail Authority.

The company, which is based in Newcastle, has also been boosted by its bus division, with profits up to £17.8m from £16.1m in 2001.

Further improvement is expected as congestion charging drives more passengers on to Go-Ahead's London buses.

However, Go-Ahead, which also operates bus services in Tyne and Wear, County Dur-ham, Oxford, and Brighton, said trading conditions remained tough for Aviance, its aviation ground services business.

It has suffered from the impact of September 11 on air travel but said it would not be drawn into price cutting in order to secure business.

Sir Patrick Brown, chairman, said: "The group's strategy of concentrating its public transport business in London and the South East continues to differentiate it from others in the sector. The board remains confident that the group, with its growing bus business, is ready to take advantage of further growth in rail earnings and a recovery in the environment for aviation services."