PARIS (Reuters) - A strike call among Renault's (>> RENAULT) in-house dealerships was followed by about 15 percent of the workforce on Friday, the French carmaker said, as unions pressed pay demands.

The Renault Retail Group subsidiary remained open for business with about 1,000 of its 6,800 employees observing the two-day strike, a company spokeswoman said. A CFE-CGC union official did not immediately return calls seeking comment.

All four unions at the sales division are backing the strike call to coincide with advertised "open days" when dealers wheel out special offers to shift more vehicles.

Renault's earnings have been partly sheltered from Europe's six-year sales slump thanks to the company's recession-proof low-cost cars and 43.4 percent stake in Nissan (>> Nissan Motor Co., Ltd.).

But the sales network has been hit by the collapse of the French market, still 13 percent below its 2007 peak, triggering job cuts and a 2013 wage freeze across the in-house dealerships that account for one-third of Renault's domestic sales.

This year, according to unions, Renault is proposing a core pay increase between 0.7 and 1.3 percent with the possibility of merit-based individual raises in addition.

"There is no impact on customers today," the Renault spokeswoman said, adding that dealerships were "taking orders as normal".

(Reporting by Laurence Frost; Editing by Andrew Callus)

Stocks treated in this article : RENAULT, Nissan Motor Co., Ltd.