Bus and train operators Stagecoach and National Express reported rising ticket sales as travellers looking to avoid the high cost of running cars turn to public transport.

Underlying revenue at Stagecoach's UK rail business, which includes London commuter franchise South West Trains, grew 8.7 percent in the 24 weeks to October 16, while Virgin Rail Group, a joint venture in which Stagecoach owns 49 percent, achieved a 9.7 percent sales jump in the same period.

National Express -- operator of the C2C commuter rail service running into central London -- said third-quarter revenue at its UK rail division grew 6 percent.

We have delivered good revenue growth and further improvements in efficiency and we have clear plans to continue to improve revenue and profitability in the future, Dean Finch, National Express chief executive, said.

Rival transport group Go-Ahead last week said new passengers looking to avoid the high cost of running cars had helped boost first-quarter trading.

The economy has barely grown since September last year and a recent Reuters poll showed economists saw a one-in-three chance it would slip back into recession.

There aren't any signs of a slowdown despite macroeconomic weakness ... as with Stagecoach, the underlying strength of the (National Express) business looks strong, said Deutsche Bank analyst Geoff van Klaveren.

National Express was stripped of the East Coast rail route by the government in 2009 but said it would re-bid for its C2C franchise, which expires in 2013.

Sales at the UK bus businesses of National Express and Stagecoach grew around 2 percent.

Stagecoach said its U.S. coaches operation posted a 12 percent leap in like-for-like revenue in the five months to September 30, while third-quarter revenue at National Express's America school bus business rose 10 percent.

Shares in National Express were 1.8 percent down by 0920 GMT, while Stagecoach shares were 2.8 percent lower, against a 2.4 percent drop in the FTSE All Share index <.FTAS>.

Earlier on Tuesday, the Competition Commission said its investigations showed that three unidentified bus companies had engaged in anti-competitive behaviour to protect core areas of business in northeast England.

The regulator previously said the UK bus market should be opened up.

(Editing by James Davey and David Holmes)