Sales in May fell to 87,733 vehicles, while they fell 11 percent to 436,961 in the January-May period, the U.S. automaker said.

Despite the weak May figures, Ford sales are "on track" to grow for the second-quarter overall, said Peter Fleet, Ford's Asia Pacific sales chief, in a written statement.

"We've strengthened our marketing plan in China for the second quarter, with new and exciting customer promotions for Ford-branded vehicles," Fleet said.

The plan includes a "realigned Kuga (sport-utility vehicle) customer offer," the statement said, without elaborating. In the automotive industry, "promotions" and "offers" generally indicate price discounting.

China's auto market, the world's largest, faces slower growth this year as a tax incentive for small-engined cars is rolled back, with sales rising 4 percent for the market overall in the first four months of the year, according to the latest data available from the China Association of Automobile Manufacturers.

Sales at Ford's U.S. peer General Motors have also fallen this year, while Japanese rival Toyota Motor Corp's sales growth has slowed.

Fleet is set to become Asia-Pacific and China chief for Ford on July 1 in a global management shake-up after the dismissal of Chief Executive Mark Fields as the company's sales come under increasing pressure globally.

James Hackett, a former office furniture executive heading Ford's self-driving car unit, was named CEO last month with a slate of other leadership posts also set to change hands.

Several key models are reaching the end of their life cycles and dragging on sales, including the Kuga and EcoSport in China's fastest growing sport-utility segment as well as the Ford Focus sedan, said Yale Zhang, Shanghai-based managing director for consultancy Automotive Foresight.

Sales of all three models have fallen by double-digits year-on-year for January to May.

"From the second half and into next year they will launch some newer generation products and the situation will be better," Zhang said.

A new version of the Ford EcoSport will launch later this year in China, a Ford spokeswoman said.

(Reporting by Jake Spring and Norihiko Shirouzu; Editing by Muralikumar Anantharaman)

By Jake Spring and Norihiko Shirouzu