Eurostar has hiked quarterly sales by 7% per cent amid sluggish nine-month passenger growth.

The high-speed rail operator between London, Ebbsfleet, Ashford, Paris and Brussels boosted revenues to £197m in the three months to September, up from £183m in the same period a year ago.

Sales for the year to date grew by 5% to £617m (£588m - 2010).

The total number of passengers carried by Eurostar in the first nine months of the year edged up just 1% to 7.3m (7.2m - 2010).

But the comparison was distorted by the impact of ash cloud disruption in 2010, and Eurostar said the underlying increase in passenger numbers for the first nine months of 2011 was 3%.

Eurostar's chief executive Nicolas Petrovic said: "We have delivered a solid performance during both the third quarter and the year as a whole although the tough trading environment across Europe demands a cautious watching brief."

Business passengers pushed up sales by 2% but Eurostar said it remained cautious about the outlook in a "challenging business environment."

The number of leisure travellers for the year to date grew by 2%.

There was strong growth in international passenger numbers, up 21% for the year to date and 15% for the third quarter compared with same periods in 2010.

Eurostar said this reflected the continuing popularity of London and Europe. It expects this to increase in the run-up to the Olympic Games.