Without diesel costs, VW said 2015 would have been a good year (Photo: VW)

Volkswagen swung to an after-tax loss in 2015 after it took a 16.2 billion euro extraordinary charge to account for costs related to its US emission-test cheating.

The German carmaker said after-tax earnings swung to a 1.36 billion euro loss in 2015 from a profit of 11.07 billion euros the year before.

VW said the special charge was for emissions-related costs, including "technical modifications and customer-related measures as well as global legal risks."

The carmaker reached a preliminary agreement with US authorities this week to either fix the 500,000 diesel vehicles affected in the country or buy them back.

VW admitted last September that it had installed software on 11 million of its vehicles worldwide that detects when their emissions are being tested. The software then directs the engine to run more efficiently than in real driving conditions.

VW CEO Matthias Mueller said that, without the emissions scandal, 2015 would have been a good year for Europe's largest  carmaker. "The Volkswagen Group's operations are in great shape, as the figures before special items for the past fiscal year clearly show" he said in a press statement.

Global 2015 group sales were up 5.4 pc to 213.29 billion euros and cash flow from operating activities grew 10.2 pc to 23.80 billion euros.

In 2016, VW Group expects unit sales to be roughly in line with last year's total of 9.93 million units. But it said passenger car sales revenue is likely to show "a sharp decrease."