MILAN (Reuters) - An appeals court in Venice has accepted a class action suit against Volkswagen (>> Volkswagen AG) over allegations the German carmaker understated the fuel consumption of its Golf model, an Italian consumer group said on Friday.

Consumer group Altroconsumo filed the class action in September 2014, long before Volkswagen was engulfed in a scandal over its cheating of diesel emissions tests and before it admitted last year to understating fuel consumption.

The consumer group had filed a similar class action against Fiat Chrysler (>> Fiat Chrysler Automobiles NV) that was initially rejected by a lower court, but also later accepted after an appeal.

A spokeswoman for Volkswagen in Italy said the carmaker had not yet received any formal notice on the matter from the court.

Altroconsumo said in 2014 it had done laboratory tests on a Volkswagen Golf 1.6 TDI BM model, which resulted in emissions 50 percent higher than those declared by the carmaker.

In the class action it had asked that Volkswagen be ordered to pay around 500 euros ($563) in damages to each owner of the tested model based on the assumption of an average mileage of 15,000 km per year. The sum should rise proportionally if a consumer's mileage is higher, the consumer group said.

"This forces carmakers to be more honest in their fuel consumption data tests and communication and holds them to account if they are not," said Paolo Martinello, a lawyer at the consumer group. "Beyond the wallet and environment, we are talking about people's health."

Martinello said Altroconsumo had collected more than 20,000 pre-signatures but the actual number of people who can adhere to this class action will only be known in a few months once the court has decided on the type of client that can join the case.

"Considering that since 2010 around 300,000 people have bought that Golf model, either new or used, and that we are asking for a compensation of 500 euros for each 15,000 km traveled, we could end up with potential damage requests for 450 million euros," he said.

The class action was lodged with a court in Venice, whose catchment area covers the city of Verona, where Volkswagen has its Italian headquarters.

(Reporting by Agnieszka Flak and Sara Rossi; Editing by Elaine Hardcastle)

Stocks treated in this article : Volkswagen AG, Fiat Chrysler Automobiles NV