* May car sales fall 38.7 percent, smallest fall since March
* Anfac says new government subsidy plan helping
(Adds Anfac comment, context)
MADRID, June 1 (Reuters) - Spanish car sales fell for the 13th month running in May but at a slightly slower rate than in April after the government launched a 200 million euro ($279.9 million) subsidy plan, a car maker group said on Monday.
New car sales dropped 38.7 percent to 71,161 units in May from 116,112 in the same month last year, Spanish car manufacturers' association Anfac said in a statement.
That compares with a 45.6 percent drop in April and is, along with March, which also fell 38.7 percent, the smallest fall since September, when sales were down 32 percent.
In May, Spain began a programme offering 2,000 euro subsidies to new car buyers, struggling with credit restrictions and soaring unemployment.
ANFAC said the plan helped some car sale segments during its first two weeks and expected it to have a greater impact on overall data starting in June, after monthly falls of around 40 percent or more since last October.
"It's hoped the significant increase in visits to dealerships since the plan began will materialise in June figures," ANFAC said in the statement.
Plan 2000E began on May 18, with car buyers getting a 500-euro subsidy from the government, 500 euros from the respective regional government and another 1,000 euros from the manufacturer.
The programme is in addition to the government's 700-million euro Plan-Vive, which subsidises the acquisition of energy-efficient cars and replacement of old vehicles.
ANFAC said it expected the Plan 2000E to boost 2009 sales by 100,000 units. ($1=.7146 Euro) (Reporting by Andrew Hay; editing by Karen Foster)