Emap has agreed to sell its consumer magazines and radio businesses to German publisher Bauer for £1.14 billion (€1.58 billion), but dropped plans to sell its business-to-business unit, hitting its shares.
Analysts had expected Emap to raise around £1.2 billion from selling Emap Communications, its business-to-business (B2B) unit which publishes trade magazines and is Britain's biggest organiser of trade exhibitions.
Emap shares fell almost 10 per cent in early trade. At 9.25am, they were down 8.4 per cent at 746 pence.
Earlier this year Denis O'Brien's Communicorp bought Emap's Irish radio stations - Today FM, Highland Radio and FM104 - for €200 million. Communicorp it is looking to offload FM104 to comply with competition regulations.
Emap said it would return around £1 billion pounds - or about 460 pence a share - to shareholders following completion of the deal with Bauer.
"Emap assessed all options for Emap Communications, including a possible disposal," the firm said in a statement.
"However, the board believes that the best value for shareholders will be achieved through continuing to operate this focused business on a standalone basis and accordingly, the board has terminated all discussions with parties interested in Emap Communications."
Emap has long been tipped as a break-up target, following a string of profit warnings as it struggles with competition from the Internet and a weak advertising market. The sudden departure of chief executive Tom Moloney in May triggered several expressions of interest in its businesses.
Emap said Derek Carter, chief executive of Emap Communications, would become group chief executive after the disposals. Alun Cathcart, currently group executive chairman, will revert to a non-executive role until a new non-executive chairman is found.