* Diluted NAV down 37 percent to 439 pence per share
* Loss before tax of 52 million pounds
* Says continues to operate within banking covenants
(Adds analyst comment, share price)
By Farah Master
LONDON, Nov 27 (Reuters) - British property firm Quintain Estates and Development said it was experiencing the most difficult conditions ever, as it posted a sharp fall in net asset values, a key industry measure, and a big first-half loss.
Quintain, responsible for some of Britain's largest urban regeneration schemes, in London's Wembley and Docklands areas, said its diluted NAV fell 37 percent to 439 pence per share at end-September.
It made a pre-tax loss of 52 million pounds ($80 million) in the six months to end-September, after a 4 million pound loss in the same period in 2007.
Quintain said valuations of its directly-held properties fell 20 percent to 869 million pounds, with valuations in its Greenwich and Wembley regeneration schemes falling 30 percent since 2007.
Latest Investment Property Databank (IPD) data showed commercial property prices dived a record 4.3 percent in October, taking the market's total decline from a June 2007 peak to more than 28 percent.
"The fear of course, was that the company might go bust. There is a sense of relief that there is nothing scary in the figures," an analyst at Arbuthnot Securities said.
Quintain's shares, which have underperformed other listed UK real estate companies by 87 percent over the past 12 months, were up 0.7 percent at 37.25 pence by 0950 GMT, having spiked to 41.5 pence in early trading.
Quintain chairman John Plender said in a statement: "We continue to operate within our banking covenants. We recognise that the market remains challenging".
Quintain, which operates in regeneration, fund management and asset acquisition, said it continued to bring cash into the business through asset sales, and was in early talks with equity partners for its Wembley site.
The firm reported it managed to increase funds under management by 6 percent, despite the troubled market.