Shares in Baltimore Technologies plc surged 36 per cent yesterday after the troubled internet security firm said it had received several approaches for its Content Technologies business.

Britain's SurfControl, whose software helps firms block employee access to pornographic websites, said on Tuesday that it was considering a bid for Content, which was put on sale by Baltimore last month. "We have had several expressions of interest for the Content business," a Baltimore spokesman said.

"But we are not confirming or denying whether SurfControl has contacted us."

Baltimore bought Content, which provides e-mail screening software, for £700 million sterling (€1.1 billion) in stock last year, but decided to sell it as part of its restructing to weather the business downturn.

Baltimore shares, which peaked at £15 at the height of the technology boom early last year, jumped 36 per cent to 19 pence by lunchtime yesterday before falling back later. The stock was already up 18 per cent on the report of SurfControl's possible bid.

This values the firm at about £113 million.