German automaker Volkswagen said on Friday global sales of all its brands rose by 3.7% in January compared to the same month last year, although they worsened in the US which is at the centre of a pollution cheating scandal.

The group sold 847,800 vehicles worldwide last month, with sales of VW vehicles alone climbing by 2.8%.

In China, the carmaker's largest market, sales jumped 14% to a record 400,100 vehicles.

"Developments on world markets at the beginning of the year are mixed," chief executive Matthias Mueller said in statement.

While sales were gaining "regaining momentum" in China, according to Mueller, the performance worsened in January in the US, which is at the centre of the scandal of rigging pollution controls, with sales falling by 7%.

The company has admitted fitted 11mn diesel engines worldwide with devices aimed at cheating emissions tests, and is facing penalties there that could reach more than $20bn.

VW sales there plunged by 15.3% in November after the scandal broke, but clawed back to a 2.0% drop in December.

The company said "the sales stop for several models with diesel engines had an impact" in January.

Mueller, however, expressed concern about markets where the trend is much worse.

The VW chief executive said "the situation in Brazil and Russia remains tense".

Sales in Brazil, which is stuck in a recession and whose currency has slumped to record lows against the dollar, sales have plunged nearly 39%. In South America overall they are down nearly a third.

In Russia, where demand has been battered by falling oil prices and a weak rouble, sales were down by over 29% in January.

European sales overall climbed by 1.8% in January.