French pharmaceutical giant Sanofi reported a healthy rise in profits on Tuesday thanks to the strong dollar, benefitting from a foreign exchange windfall.

Sanofis' net profit for 2015 came in at 7.4 billion euros ($8.3 billion), up 7.7 percent from the previous year.

Much of Sanofi's earnings are in dollars, resulting in higher profits when converted into euros, the company's reporting unit, during times of greenback strength.

Stripping out currency factors, earnings fell 0.9 percent.

Sanofi's sales were 37 billion euros, somewhat below analysts' expectations.

Sanofi's rare disease division Genzyme, which it acquired in 2011, continued to underpin the group's overall performance with a turnover rise of close to 30 percent.

But sales of Sanofi's flagship anti-diabetes drug Lantus suffered from competition from generics.

But Sanofi's own generic drugs sold well, mostly in emerging markets, as did vaccines, the company said.

Animal health also had a good year, but Sanofi is still hoping to spin off its animal health unit Merial, in a swap for the consumer health unit of German peer Boehringer Ingelheim.

Net profit in the fourth quarter alone was 1.7 billion euros, down 6.5 percent.

For 2016, Sanofi said it expects earnings per share (EPS) to be "broadly stable", excluding currency factors.

Last November, Sanofi warned that profits would stagnate for the next two years during a major restructuring drive, which would include a streamlining of its product portfolio, cost cutting and job cuts.