The top 10 ISPs in the UK have more than 88 per cent of the UK broadband market between them and that share is increasing, according to a survey of the industry.

A study by Point Topic's UK Plus service found that by the end of March 2006 the top 10 ISPs accounted for 9.5 million broadband lines out of a total UK market of 10.7 million. 

The companies added 900,000 lines and increased their market share by one per cent in the first quarter of 2006, with BT Retail one of the main gainers.

Three of companies in the top 10 (NTL, Telewest and Virgin.net) are all part of NTL Telewest. 

If these figures were taken as one, it would create the biggest UK ISP with three million customers compared with 2.5 million for BT.

UK Plus said that the trends in its report would concern Ofcom and others, which would like to see wider competition in the broadband market instead of the increased consolidation seen in 2006. 

"It remains to be seen whether increasing the take-up of local-loop unbundling, and the entry of Carphone Warehouse and other providers of 'free' broadband services, will change the picture," said a UK Plus statement. 

Biggest broadband ISPs in the UK by number of lines:

BT Retail 2,481,000
NTL 1,726,000
AOL 1,300,000
Telewest 1,096,000
Tiscali 1,085,000
Wanadoo 986,000
Pipex 311,000
PlusNet 194,000
Virgin.net 193,000
Tesco 132,000
Others 1,227,000