The board of Informa on Thursday rejected its second offer in two years, turning down a 450p a share approach from a private equity consortium led by Providence Equity Partners, saying the price “significantly undervalued” the business information group that publishes Lloyd’s List.

The consortium, originally made up of Providence and Carlyle Group – and later joined by Blackstone – first approached Informa at the start of July with a 506p a share indicative proposal valuing the deal at £3.4bn. However, tumbling markets forced it to cut the offer by almost 10 per cent, valuing the company at closer to £3bn.

Peter Rigby, chief executive of Informa, said the offer, which was tabled yesterday morning, was promptly rejected following soundings from larger shareholders. Mr Rigby said: “The business going forward is well positioned to grow and deliver value to shareholders.”

Shares in Informa closed down 35¾p at 414½p on fears that a deal was now looking increasingly unlikely.

A price of 500p was estimated by bankers who had studied Informa’s books to achieve a return on equity of 14 per cent – well below private equity’s typical 20 per cent minimum target for returns.

The Informa board was coming increasingly under pressure yesterday. It held discussions with United Business Media in June but the parties were unable to agree terms and its rival walked away. The company was also approached in October 2006 by 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 £4bn.

Shareholders backed its rejection of the Springer offer but this could have subsequently clouded the latest calculations as Informa’s board debated whether to recommend or reject a new offer at a substantially lower price than what was on the table less than two years later.

David Gilbertson, co-founder and former chief executive of Informa who now heads Emap, the private business-to-business company owned by Apax and Guardian Media Group, said he believed the board had done the right thing.

“I think they know they have a good resilient business and I think the shareholders will respect that,” Mr Gilbertson, who still owns several hundred thousand shares himself, told the FT.

“Actually, if they had gone to shareholders recommending a much lower offer, that might have been harder. They have been pilloried for having debt levels that in private equity terms would be seen as pretty low.

“They have just reported some pretty solid results and paid a generous dividend. I would not expect there to be an excessive reaction from shareholders.”

Mr Gilbertson founded Informa with Mr Rigby, who became chairman, when LLP Group and IBC Group merged in 1998.

Bank financing for the acquisition, led by JPMorgan Cazenove, is understood to be in place.