Shares in Blenheim jumped 52.5p to 420p on the news, making them the day's best performers in the FT-SE 250 index. They have been on a roller- coaster ride since takeover rumours first surfaced more than three months ago.
Blenheim made its latest statement in response to weekend press comment and added "a further announcement will be made when appropriate".
Reed Elsevier, the Anglo-Dutch publisher, is understood to have made a renewed bid approach to Blenheim, only three weeks after previous takeover talks were terminated.
Reed is reported to have held talks with Blenheim to see if any common ground could be reached on a price for an agreed takeover.
Last month Blenheim called off talks with Reed and with Lord Hollick's United News & Media, saying it had received no proposals it could recommend to shareholders.
However, United is said to have continued negotiations with Blenheim, though neither United nor Reed has ever formally admitted they were engaged in talks.
Reed's latest move appears to be an attempt to try to wrong-foot United. "It's got to the stage where it is the last one to blink," said a source close to the discussions.
Previously Reed, which entered the fray after United, was thought to be biding its time in the hope that Blenheim's chairman, Neville Buch, would drop his asking price, said to be a bid worth at least 490p a share, valuing the company at pounds 500m.
Blenheim shares hit 458p at the height of the bid speculation at the beginning of June, having run up from as low as 250p earlier this year on takeover rumours, but they collapsed by more than 100p to pre-bid levels when the talks were broken off.
Any deal would have to be agreed as 40 per cent of Blenheim's shares are controlled by the directors and Generale des Eaux, the French water company
Unlike its last announcement, when it described its first-half performance as strong, Blenheim gave no indication of current trading.
Interim results for the six months to June are expected on 2 October.