JOIN USThe law was published in the government's Journal Official today, meaning Sarkozy has signed it and it has formally gone into effect. The constitutional watchdog approved the plan a day earlier, and France's parliament gave the measure its backing on October 27.
Unions argued that retirement at 60 was a cornerstone of France's generous social benefit system, but the government says the entire pension system is in jeopardy without the reform because French people are living longer, an average of nearly 85 years for women and 78 for men.
Sarkozy said in a statement today that France's pension system had been "saved".
He said he was "fully aware that this is a difficult reform. But I always considered that my duty, and the duty of the government, was to carry it out."
Like many heavily indebted European governments, France is trying to cut back on spending. The French reform is the latest successful push by a European government to cut back on government spending despite months of local anti-austerity strikes and protests.
French union workers and others angry over the reform had disrupted train and air travel, caused gasoline shortages and led to a garbage pileup in the southern city of Marseille.
Successive nationwide street demonstrations drew more than a million people at a time.
The French reform means that the minimum retirement age is now 62 instead of 60. Those who want to claim full-fledged pension benefits must now wait until age 67 instead of 65.