The latest quarterly survey by the Roadtodata Euro Index (formerly eurocarprice.com) shows that by comparison, average new car prices across Europe as a whole increased by 1.3% over the same period.
Rick Yarrow, director of analysis services for Roadtodata, said: "Car price increases slowed significantly in the UK. They were up just 0.5% year on year as the market continued to decline.
"This contrasts with the previous quarter, when average prices for new cars in the UK were 5.6% higher compared with a year earlier - the second- highest rate of increase in Europe."
Price increases in the year to June 2006 were highest in the executive car segment. Petrol model prices were slightly below those of diesel, although petrol sales fell by 10.4% while diesel volumes increased by nearly 7%. Diesels now accounts for 37% of the total UK market – below the European average.
"Overall, the average price of a new car in Britain is 1% below the average in the euro currency zone.
"The total new car market was 4.2% down compared with the same period in 2005. Sales fell in nearly every market segment and body style," said Yarrow.