DEARBORN, Michigan — Ford Motor Co.said on Thursday it will increase production over the rest of the year after a surge in sales triggered by the US government’s “Cash for Clunkers’’ sales incentive program.

Ford has emerged as one of the clear winners from the $3 billion sales program, which offers rebates of up to $4,500 for consumers who trade in older and less fuel-efficient vehicles.

But like other automakers, Ford was caught off guard by the incentive-fueled jump in sales that began in late July and raised the prospect that the battered industry had hit bottom.

In response, Ford said on Thursday it will build another 6,000 Focus sedans in the current quarter by adding overtime and a Saturday shift at an assembly plant in Wayne, Michigan.

And a second plant in Kansas City, Missouri, will drop plans to shut down for two days later this month and increase output of the Escape small SUV by another 3,500 vehicles.

The moves take Ford’s third-quarter output in North America to 495,000 vehicles, up 18 percent over a year earlier.

The No. 2 US automaker also set a fourth-quarter production target of 570,000 vehicles. That would represent a 33 percent annual gain.

“I think we were surprised by the speed and the urgency with which consumers went to dealers,’’ said Ford sales analyst George Pipas.