PARIS -- The head of U.S. tiremaker Titan sparked an uproar in France on Wednesday by mocking French workers for putting in only "three hours" a day and saying it would be "stupid" to invest in the country.

Titan chief executive Maurice Taylor's incendiary remarks came as France's economy is struggling in the face of increasing global competition, with leading companies announcing thousands of job cuts in recent months.

The country's Socialist government has vowed to tackle France's productivity gap -- blamed by critics on high wages and reduced working hours -- but is facing opposition from powerful labor unions.

The letter from Taylor to French Industrial Renewal Minister Arnaud Montebourg was in response to a request for Titan to consider investing in a loss-making Goodyear tire plant in Amiens, northern France.

"I have visited that factory a couple of times. The French workforce gets paid high wages but only works three hours," Taylor said in the letter, dated February 8 and obtained by French business daily Les Echos.

"They get one hour for breaks and lunch, talk for three and work for three. I told this to the French union workers to their faces. They told me that's the French way!"

Montebourg responded with a angry letter of his own Wednesday calling Taylor's accusations "extremist" and threatened to watch over the company's exports to France with "zeal."

"Your extremist insults display a perfect ignorance of what our country is about," the minister said in a letter seen by AFP.

"Be assured that you can count on me to inspect your tire imports with a redoubled zeal," he added.

Goodyear (IW 500/54) said last month it was set to close the plant, which employs 1,173 workers, following five years of failed talks with unions.

Taylor said Titan had a long history of buying and turning around troubled factories but in this case was not in any way interested.

"Sir, your letter states that you want Titan to start a discussion. How stupid do you think we are? Titan is the one with the money and the talent to produce tires. What does the crazy union have? It has the French government," Taylor wrote.

The standard length of the working week in France is 35 hours.

Taylor told AFP later that France was doomed.

"I just came back from Australia and I met their young Frenchmen and women and young Spanish men and women who have moved there because they can get jobs down there and they're excited to build something," he said.

"That's why in France pretty soon everybody will be sitting down in cafes sipping a glass of wine but they won't be making any money."