The private equity consortium attempting to buy Informa have been ordered by the Takeover Panel to reveal their intentions by 26 September.

Last week, Informa rejected a reduced 450p a share offer from the consortium, consisting of Providence Equity, Carlyle and Blackstone, which the publishing group believed significantly undervalued the company. The consortium, which had previously proposed an offer of 506p per share, responded by saying it was disappointed by the quick rejection of its proposal.

Sources close to the private equity bidders said the consortium would have difficulty coming back with an offer high enough to satisfy the board. Shares in Informa fell 11.5p, or 2.88 per cent, to 387.5p by the close of markets today. There are concerns that Informa's share price will plummet if the private equity consortium withdraw from the process.

The company rejected a previous approach in October 2006 from Springer Science and Business Media, the academic publisher owned by Cinven and Candover, with a 630p a share offer that would have created a European publishing group worth more than £4 billion.

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