BT has expanded its online directory business with the £20m purchase of Ufindus as it moves to exploit Yell's recent run of weak results.

Ufindus, bought from Iomart Group, has more than 1.9 million listings and brought in revenues of £14m last year.

It has more than 20,000 SME customers and receives more than nine million searches a month.

BT sold Yell for more than £2bn in 2001 to reduce debts, but now wants to re-enter a market where it believes it can capitalise on Yell's weakness – Yell's shareprice has fallen 50 per cent in the past 12 months because of bad results.

While its paper directory business is suffering, Yell's UK online business grew by 45 per cent last year and the company is fast switching its focus to the internet.

BT has been testing a service called BT Exchanges which as well as providing searchable business details will allow businesses to network with one another. It is expected to launch later this year.

"Ufindus will play an important role in the continued development of BT Directories' online portfolio," said David Benjamin, head of BT Directories.