* Car sales in Europe (EU27+EFTA) fall 8.5 pct in Aug
* Ford sales fall 29 pct in Europe in Aug
* GM's Opel sales fall 19 pct, Chevrolet down 13 pct
* Renault Group sales drop 13 pct, PSA shrinks 12 pct
By Laurence Frost
PARIS, Sept 18 (Reuters) - European car sales fell 8.5 percent in August, for an 11th straight monthly decline led by Ford, General Motors and Fiat and mid-market brands bore the brunt of the slump in markets including Italy, France and Germany.
The region recorded 722,483 registrations last month, the Brussels-based Association of European Automakers said, compared with 789,458 a year earlier. Sales for the first eight months fell 6.6 percent to 8.59 million vehicles.
Ford had the worst August among major automakers, with sales plunging 29 percent year-on-year. European registrations always hit a seasonal low in the biggest summer vacation month.
The U.S. automaker is considering factory cuts even as it prepares to roll out new models to halt mounting losses and falling market share in the region.
"We are looking at all elements of the business, including cost," Ford of Europe chief Stephen Odell said earlier this month.
General Motors, which is also preparing job cuts and an eventual factory closure in talks with unions at its Opel brand, saw total registrations drop 18 percent last month, matched by the sales decline at Italy's Fiat.
With the exception of Spain, austerity-strapped markets worst hit by the debt crisis continued to suffer, with registrations contracting 20 percent in Italy and 11 percent in France, while British sales were little changed.
Spanish sales rose 3.4 percent as customers rushed to complete purchases ahead of a Sept. 1 sales tax increase - but have since plunged 28 percent, according to car retailers' association Ganvam.
German car sales, which had long resisted the European market collapse, shrank 4.7 percent in August, close to July's 5 percent decline.
Shrugging off its domestic market downturn, Volkswagen continued to claw business from weaker rivals with a 1.6 percent gain led by luxury marque Audi's 8 percent advance.
The Wolfsburg-based group, which aims for over 10 million global vehicle sales in 2018 to grab the world no.1 ranking from Toyota, achieved a 25 percent European market share so far this year, up 1.8 points on the same period of 2011.
Daimler's Mercedes-Benz eked out a sales growth of 0.5 percent, while a faltering performance by BMW's Mini brand led the Munich-based automaker 12 percent lower.
Besides a handful of premium brands, the only winners in Europe's tough sales environment are low-cost cars and relative newcomers such as South Korean affiliates Hyundai Motor and Kia Motors - whose combined registrations rose 3 percent last month.
While PSA Peugeot Citroen registrations fell 12 percent and Renault tumbled 13 percent, led by the namesake brand's 21 percent plunge, sales by Renault's no-frills Dacia unit surged 16 percent.