Update 1330: Emap shares jumped to 854p, up by 11.92%, a leap of 91p from yesterday's close of 763.5p.
The company issued the following statement this morning: "The board of Emap today announces that, in response to various unsolicited proposals it has received recently for parts of the group, it is undertaking a review of Emap's group structure and portfolio of assets.
"All options to maximise shareholder value will be examined, including a possible sale or demerger of some or all of its constituent businesses. Citi and Lazard have been retained by the board of Emap to assist on the review."
It said it will continue its search for a new chief executive in tandem with this process.
The decision puts into play some of the biggest brand names in magazines and radio, such as FHM, Heat and Magic. The consumer side of the company is likely to be hived off from its business-to-business division, which generated around a third of the total revenues of £884m in 2006/2007.
The magazines division has been hit by changing media consumption habits, especially those of young men who have lost interest in magazines such as FHM and Max Power. This week Emap unveiled a revamp of FHM to attract new readers.
The change in consumption habits has hurt ad revenues, which according to the company's latest information were down 13% year on year in the April-June quarter.
The radio division has also experienced its own ad revenue difficulties amid general malaise in the sector, but is the second biggest radio group in the UK. It boasts good listener figures for its big brands such as Magic and Kiss, and is strong in digital radio.
The radio business might be the subject of the approaches cited by Emap. Last month, it was reported that former chief executive Tom Moloney had held talks with the biggest radio group GCap Media about a radio merger, while another potential partner is Global Radio. Global was established last month to acquire Chrysalis Radio, and is chaired by Charles Allen, the former ITV chief executive.
Emap's multi-platform strategy may complicate matters, because it has extended brands such as FHM and Heat beyond the core magazine into television, mobile, and the internet.
Earlier this week, it sold a 50% share in its music TV stations, which include Smash Hits, Kerrang! and Kiss, to Channel 4 for £28m.