TalkTalk says 4 percent of customers' data accessed in attack

A company logo is seen on a TalkTalk building in London, Britain October 23, 2015. REUTERS/Stefan Wermuth -

LONDON (Reuters) - TalkTalk, the British broadband company hit by a cyber attack last month, said the personal data of only 4 percent of its 4 million customers was put at risk, much lower than was originally feared. The company said it had been "a difficult decision" to notify all customers of the risk before it had established the real extent of any data loss, but it believed it had a responsibility to warn customers. It said on Friday the total number of customers whose personal details were accessed was 156,959, and 15,656 bank account numbers and sort codes were stolen. Shares in TalkTalk, which had fallen 18 percent since it disclosed the hack on Oct. 22, were trading up 5.5 percent at 233.1 pence at 8.37 a.m. BT. (Reporting by Paul Sandle; editing by Kate Holton)