By Matt Falloon

LONDON (Reuters) - Surveyors reported the most widespread fall in house prices last month in the 30-year history of their RICS market survey, suggesting the property downturn is gathering pace.

Sterling fell to a fresh record low against the euro after the Royal Institute of Chartered Surveyors survey on Tuesday as investors fretted the weak housing market would take its toll on the broader economy.

The net balance of surveyors reporting falling, rather than rising, house prices deteriorated to -78.5 in the three months to March from -65.7 in February -- the lowest since the survey began in January 1978 and well below forecasts for a reading of -67.5.

"The risks of a serious housing-led slowdown in the UK are rising by the day," said George Buckley, chief UK economist at Deutsche Bank.

Prime Minister Gordon Brown is due to meet top retail and investment bank executives in London on Tuesday to discuss the impact of the global credit crisis ahead of a trip to the United States.

The RICS figures, released at the same time as a gloomy retail sales survey from the British Retail Consortium, are likely to reinforce expectations the Bank of England will need to continue cutting interest rates this year, after trimming rates by 25 basis points to 5 percent last week.

The BRC survey showed like-for-like retail sales fell in March for the first time in two years.

Britain's biggest mortgage lender Halifax said last week that house prices fell in March at their sharpest pace since the recession of the early 1990s as the credit crunch forces banks to toughen up mortgage terms and begins to hurt consumers.