BT looks set to roll out the controversial targeted advertising system Phorm across its network before the end of the year, according to the Phorm chief executive.

The Phorm system tracks users' online surfing habits and then delivers relevant adverts - a practice that's raised a number of concerns from privacy campaigners. However, Phorm claims its 'anonymises' the information about web users so they are impossible to identify.

The ISP trialled the service from September to December, with 10,000 BT customers given the option to take part.

Kent Ertugurl told the Dow Jones newswire: "We're not able to comment on specific timings but our work with BT is the most advanced. It'll most definitely be online by the end of the year".

However, BT said it hasn't identified the exact timeframe for rolling out the scheme and is still evaluating the outcome of the trial.

The trial held last year was the not the first to be undertaken by BT. The ISP came under fire after it was revealed in April that it had held secret trials of the service, tracking more than 30,000 users in two separate tests that took place in 2006 and 2007.

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