Media regulator Ofcom has announced a review into UK television advertising ahead of changes to European regulations.

The current rules, set out in the Television without Frontiers Directive, permits broadcasters to show up to 12 minutes of advertising in any one hour, subject to a total average of 9 minutes an hour.

Public service channels may show 12 minutes of advertising in any one hour, but must only show an overall average of 7 minutes an hour, and a specific average of 8 minutes an hour between 6pm and 11pm. Particular rules apply to GMTV, and similar rules on scheduling apply to both public service and non-public service channels.

The relaxation of restrictions in the European rules, as set out in the draft of a new Audio Visual Media Service Directive, reflects the growing competition faced by commercial broadcasters across Europe for advertising revenue.

Ofcom says this will be taken into account when considering new rules applying to UK-licensed broadcasters, but will also recognise the "possible concerns of viewers about the amount and intrusiveness of television advertising."

The review will also look at the frequency of advertising, and how much advertising can be scheduled across the day and in any one hour. Though Ofcom will consider the amount of advertising, it says there will be no change to the 12-minute rule.

Ofcom will assess the impact of different options on the broadcasting industry, taking into account the Office of Fair Trading's review of Contracts Rights Renewal, which starts at the beginning of 2008.

The regulator is hoping to publish its proposals on changes to TV advertising in early 2008, with a view to implementing any changes to the amount of advertising by January 2010, with advertising scheduling changes to be implemented by January 2009.