More than half of European websites selling consumer electronics are misleading or cheating online shoppers, the European Union consumer watchdog said on Wednesday after checks on 369 sites in 28 countries.

National regulators will now force them to amend their selling practices and could close such sites if they fail to comply.

About a quarter of European online shoppers use the Internet to buy electronic products such as digital cameras, mobile phones or DVD players, creating a market worth around 6.8 billion euros ($9.9 billion) a year.

There is a lot of work to be done in the months ahead to clean up this sector, EU Consumer Affairs Commissioner Meglena Kuneva said in a statement. I know from my own mail bag ... that these are a real problem area for consumers.

Checks carried out by national authorities in May showed that 55 percent of the websites investigated -- including 200 of the biggest -- were misleading buyers about their consumer rights or shipping costs, or gave incomplete contact details.

The checks took place in 26 EU countries plus Iceland and Norway.

About two-thirds of the problem websites failed to inform, or misinformed, buyers about their right to cancel an order within a minimum of seven days and return the product without reason.

About a third of problem sites did not properly give their address or contact details, which meant buyers could not contact them if they had problems with the goods.

(Reporting by Pete Harrison; Editing by Dale Hudson)