Swiss food giant Nestle said Thursday its net profits had plunged by a lower-than-expected 39 percent last year due to a strong Swiss franc.

Net profit stood at 9.1 billion Swiss francs, lower than the 9.8 billion Swiss francs (8.2 billion euros, $ 9.1 billion) forecast by analysts.  

The company said the lower net profits were "mostly due to the one-off impact from the disposal in 2014 of part of the L'Oreal stake."

The French cosmetics firm in 2014 bought back an eight-percent stake that Nestle owned in L'Oreal, boosting the share of the family of heiress Liliane Bettencourt in the company to 33.3 percent.

But the Vevey-based firm said organic growth, the real measure of a company's performance, was good at 4.2 percent and was "supported by increased momentum in real internal growth combined with continued margin improvement," according to chief executive Paul Bulcke.