ROME, Jan. 17 (Xinhua) -- Italy's Antitrust Authority has fined six online travel agencies more than 4 million euros for unfair practices and violating consumer rights, the Italian regulator said in a statement.

The Authority said the six websites -- www.it.lastminute.com, www.volagratis.com, www.opodo.it, www.govolo.it, www.edreams.it, and www.gotogate.it -- failed to provide users with "understandable information".

They also charged commissions for credit card purchases, a practice which "acts as a brake on the development of e-commerce and imposes a transaction cost that consumers cannot avoid", the Authority said.

As well, the Italian regulator found the websites charged excessively for customer assistance phone numbers that were only available after a purchase was made, and failing to provide email addresses with which they could be reached by consumers.

The Authority's move came after an investigation sparked by consumer complaints and a European Union-wide check on 352 travel websites coordinated by the European Commission, the EU's acting branch.