PARIS—Renault SA Friday said its net profit jumped in 2015 on improved sales and reduced costs despite the French auto maker's €620 million ($700 million) shares of the net loss incurred by its Russian automotive joint venture with partner Nissan Motor Co.

The auto maker, part owned by the French state, warned that global demand for new cars is set to slow this year, particularly in Europe after a 9.3% jump in sales last year, with further declines in Brazil and Russia, two of Renault's most important foreign markets.

Renault is still aiming to improve revenue, profitability and generate cash flow at its automotive business after capital expenditure this year.

Renault said its net profit rose 49% to €2.82 billion euros in 2015 as its revenue rose more than 10% to €45.33 billion, helped in large part by a robust recovery in the European car market. The company said its operating profit margin rose to 5.1% from 3.9% partly from a €527 million reduction in operating costs.

Renault said it is in talks with other shareholders in Russia's AvtoVAZ, whose sales have tumbled as the Russian economy has fallen into recession, about injecting cash into the car manufacturer. Renault and Japanese partner Nissan have joint control of the company. Financial support for AvtoVAZ could take the form of a debt-for-equity swap, Renault said.

Renault has proposed a dividend of €2.40 a share, up from €1.90 last year.

The much improved financial performance at Renault could help blow away regulatory clouds hanging over the company. Renault is to recall more than 15,000 vehicles to repair their emissions-control systems after a government investigation into whether auto makers have exceeded France's pollution limits.

The French government up the commission last October, in the wake of the Volkswagen AG emissions scandal, to test 100 cars under real driving conditions. Some models made by Renault and several foreign car brands were among those found to have excessively high exhaust emissions that didn't correspond to the level of emissions recorded under laboratory conditions.

Write to Inti Landauro at inti.landauro@wsj.com

(END) Dow Jones Newswires

February 12, 2016 03:05 ET (08:05 GMT)