Transport group Stagecoach said it planned to spend £71 million on new buses to attract more passengers.

The orders for 584 new buses will be the biggest ever placed by the Perth-based company, which reported pre-tax profits of £84.6 million in the six months to October 31 - an increase of 9% on a year earlier.

Stagecoach said increasing car congestion, inward migration and a growing focus on environmental issues had attracted more passengers to its services, including those run under its South Western trains franchise. It also operates 7,000 buses covering around 100 towns and cities in the UK.

Stagecoach said it had invested heavily in marketing bus travel, with an 'encouraging' success rate in converting non-users to public transport. Estimated passenger volumes in the six months were 3.9% higher than the same year period a year earlier, with full fare passenger growth at 2.4% and the remainder coming from concessionary travel schemes.

Shares rose 5%, or 10.8p, to 240 pence, on Wednesday.