Channel tunnel operator Eurotunnel has shown that its finances are continuing to improve, but warns that it may miss next year's target of breaking even.

"If the present difficult environment continues, the achievement of this target could be delayed," Eurotunnel head Charles Mackay said in a statement.

For the first half, it has reported a narrowing loss of 557m French francs (£51.8m; $74m), compared with 729m francs a year earlier.

Its underlying loss, which does not include interest payments made on its debt, widened to 750m francs from 707m, Eurotunnel said in a statement.

The company also warned that the rate of growth for its freight and car shuttle services has been lower than it hoped.

The company's freight shuttle service showed a 9% increase, but passenger numbers on its car shuttle fell by 9% - a decline Eurotunnel blamed partly on the UK's foot-and-mouth crisis.

To cover its debts and expenses, Eurotunnel plans to make more money from its services division.

Illegal immigrants

Eurotunnel also issued a plea to the British and French governments for help in stopping illegal immigrants entering the UK.

The tunnel operator said it was devoting "considerable effort and resources" in its attempt to stop stowaways hiding on its shuttle service.

About £3m had been invested in security measures since the start of the year, and Eurotunnel's chief financial officer Richard Shirrefs said this meant only a handful of people had managed to cross the Channel in recent nights before being spotted.

Mr Shirrefs said the French authorities should arrest would-be migrants trying to break into its freight terminal at Coquelles, near Calais.

And he said the British Government should send stowaways who managed to reach the UK straight back to France.

The British government has threatened to fine Eurotunnel £2000 for each illegal immigrant it unknowingly brings into the country.