LONDON (Reuters) - Barclays has seen its share of UK mortgage lending soar in the first months of the year, joining other big banks that have taken advantage of turbulent conditions to boost their market share.

In a trading update on Thursday, the bank said mortgage volumes in 2008 were "significantly higher" than in 2007.

The bank, Britain's seventh-largest mortgage lender, had a share of over 20 percent of net new UK mortgage lending in the first quarter, well above its 8 percent level last year.

"We have clearly been beneficiaries in terms of current market conditions," Finance Director Chris Lucas told reporters, adding growth would continue but "not at that rate".

"The first quarter was unique in terms of the conditions."

Barclays, whose Woolwich mortgage arm lost market share until 2006, has said tougher market conditions are a growth opportunity, as specialised rivals wrestle with higher costs.

With house prices falling and funding costs rising, UK lenders have withdrawn thousands of mortgage products and raised rates, but some larger banks have also spotted an opportunity as cut-price specialists are forced to pull out.

Royal Bank of Scotland has trimmed rates and giant HSBC, which has an underweight position in UK mortgages, has launched a "rate matcher" offer that has boosted its lending to four times its normal rate in the past month.

"The important thing from my perspective is we don't chase market share for the sake of market share," Barclays' Lucas said. "We will only write business at attractive margins and at a good risk profile."

Barclays' average loan-to-value of new business was 53 percent, he said, lower than last year.