YouTube could overtake bbc.co.uk as the UK’s most popular entertainment site “within weeks”, according to Hitwise.

The measurement group says YouTube is rapidly closing the gap on the Beeb’s flagship site in terms of share of UK visits. 

bbc.co.uk has held top spot among entertainment sites in the UK for the last two years, and recorded 13% year on year growth in its share of visits in May.

However, YouTube’s share grew by a whopping 669% in the same period, and 140% in the last six months. Hitwise said:

“Last week, BBC.co.uk ranked #14 among All Categories of websites with 0.82% of all UK Internet visits compared to YouTube’s #25 ranking with 0.81% of UK Internet visits. The gap between the two websites is closing rapidly. Last week, BBC had a 1.6% lead on YouTube in share of UK visits, down from 37% three months ago and 131% six months ago.”

Although the move may well end up being billed as a watershed moment for ‘Web 2.0’ in the UK, the figures don’t include visits to BBC-owned sites outside the bbc.co.uk domain (including its news, sport and weather services), or YouTube’s off-network traffic.

The Times says figures from Nielsen//NetRatings show that the broadcaster’s entire stable of websites attracted 16m UK users in April – around twice that of YouTube.

Earlier this week, YouTube announced international expansion plans involving the launch of tailored sites for the UK and eight other countries.