YouTube says users watch more than 100 million videos a day

YouTube co-founder Steve Chen told Reuters news agency it was hoped that within 18 months the site would "have every music video ever created".

The company said it planned to offer the videos free of charge.

YouTube hosts homemade videos, but pirated commercial clips can be found. It claims 60% of videos watched online in the US are viewed on YouTube.

The site plans to allow users to add the music videos to their own profiles and post reviews.

"Right now we're trying to very quickly determine how and what the model is to distribute this content and we're very aggressive in assisting the labels in trying to get the content on to YouTube," said Mr Chen.

Unauthorised videos

Warner Music Group and EMI confirmed to Reuters that they had been in discussions about the plan.

Earlier this year, YouTube agreed a deal with US broadcaster NBC to promote its autumn schedule on the website.

The broadcaster had previously had to ask YouTube to remove unauthorised footage of its shows posted by users.

The site was named one of Time magazine's 50 "coolest websites" of the year on Tuesday.

On the day of the announcement it suffered an unplanned breakdown lasting about six hours.