By Christina Fincher

LONDON (Reuters) - The number of mortgages approved for house purchase was the second weakest on record in April, a survey shows, suggesting no let-up in the property market downtrend.

The British Bankers' Association said approvals for home loans -- a lead indicator of house prices -- nudged up to 38,704 last month from March's record low of 35,546. That was nearly 40 percent lower than at the same time last year and well below the average of the past six months.

"March was the record low and April is the second lowest ever so you cannot call that a recovery," said Michael Saunders at Citigroup.

"The housing market remains extremely weak."

House prices have been falling on a monthly basis since late last year as the global credit crisis has forced banks to tighten their lending criteria.

A scarcity of credit means mortgage rates for many borrowers are now higher than there were before the Bank of England starting cutting interest rates in December.

A report from Standard & Poor's last week showed more than a fifth of borrowers with a poor credit history falling behind on their mortgage payments.

Payment arrears of more than 90 days by such borrowers rose to 10.6 percent, suggesting home repossessions could rise sharply in the months ahead.