Quality concerns spread as west Europe wheat harvest winds down

* French wheat harvest nearly over, UK 75 pct complete

* Quality a major concern despite rising output

By Nigel Hunt

LONDON, Aug 28 (Reuters) - Western Europe's wheat harvest is nearing completion with quality concerns driven by persistant rain still centred on the region's top producer France also starting to seep into Britain, analysts say.

Britain's winter wheat harvest was 75 percent complete, as of Tuesday, while in France it is nearly over although some fields still have to be cut in regions along the sea in the northern part of the country.

"There are the first indications this week of quality starting to deteriorate following the heavy rainfall of the last few weeks," crop consultants ADAS said in a harvest progress report for the region's third largest producer on Thursday.

"However, this is only a problem in crops where harvest has been delayed for some time. Where crops are only just ripe for harvest, quality has been maintained," the report added.

"The average quality will be lower this year but we are still awaiting definitive results from some regions," Philippe Pinta, head of French wheat growers group AGPB said.

France was forced to import Lithuanian and British milling wheat last week to mix with its poor grade rain-soaked crop in a rare move aimed at meeting quality requirements under contracts signed before the harvest.

France's top client Algeria, however, has told traders it would reject cargoes containing wheat from mixed origins, raising the possibility there could be reduced sales to the North African country this season.

The latest forecasts put France's wheat crop at between 37.3 and 38.2 million tonnes. That would be at least 5 percent above the five-year average.

Traders are expecting a UK wheat harvest of between 16 million tonnes and 16.75 million, up from 11.9 million tonnes last year, boosted by both higher yields and a rise in area following more favourable planting conditions last autumn.

"Yield reports continue to be positive, with the majority of farmers reporting yields above the farm average," ADAS said.

In Germany, the EU's second largest wheat producer, about 10 to 15 percent of the crop remains to be harvested with quality less of a concern than in France, traders and analysts said.

Around two to three days would be needed to complete the harvest if weather improves but the ground is at times too soft for harvesters to drive on.

Germany will harvest 26.3 million tonnes of wheat against 25.0 million tonnes last year, the country's farm cooperatives association forecasts.

"With Germany's wheat harvest forecast at around 26 million tonnes this year, the remaining 10 percent to be harvested is around 2.6 million tonnes. This means that around 23.4 million tonnes is of acceptable quality so overall Germany is likely to have gathered a decent crop this year," one German trader said.

"There is concern about quality damage to the remaining areas of wheat to be brought in but the (the milling quality criteria) Hagberg falling numbers in the remaining wheat in the field look good, so not all the remaining volumes will fall to feed quality. Much depends on whether wheat has been knocked over by the rain." (Additional reporting by Valerie Parent and Sybille de La Hamaide in Paris, with Michael Hogan in Hamburg; Editing by Veronica Brown and David Evans)