UK house price growth slows again in March - Nationwide

(Adds details from Nationwide, comments from economist)

LONDON, March 27 (Reuters) - British house prices rose in March by the smallest annual amount since September 2013, figures from mortgage lender Nationwide showed on Friday, adding to signs the country's housing market is cooling.

Nationwide said the annual rate of increase dropped to 5.1 percent from 5.7 percent in February, the seventh month in a row that the pace of price growth has slowed.

Prices in March alone rose by 0.1 percent.

Nationwide's chief economist, Robert Gardner, said the recovery in Britain's economy, including lower unemployment and record low interest rates, were supporting the housing market.

"Nevertheless, the pace of housing market activity has remained subdued, with the number of mortgages approved for house purchase in January around 20 percent below the level prevailing one year ago," he said.

British regulators tightened rules for mortgage lending last year in a bid to cool price growth which reached nearly 12 percent in annual terms in the middle of last year.

Nationwide said prices in London and southern England again saw the strongest rates of annual growth although there was a noticeable softening in the first three months of the year, particularly in London.

In the capital, prices rose by an annual 12.7 percent in the first quarter, slowing from a rise of 17.8 percent in the last three months of 2014.

(Writing by William Schomberg; editing by John Stonestreet)