Heineken's chief executive refused to rule out a higher bid by the Dutch brewer with Carlsberg for Britain's Scottish & Newcastle, in an interview with a Dutch paper on Friday.
Scottish & Newcastle rejected a raised bid from Carlsberg and Heineken at 780 pence a share, or 7.6 billion pounds ($14.9 billion), on Thursday and said it would talk only if the offer was at least 800p.
Asked in an interview published by Het Financieele Dagblad whether negotiations could lead to a further increase in the bid Heineken CEO Jean-Francois van Boxmeer said: "You can't rule that out. It is neither a yes nor a no, that would be speculating."
"We still think that 780 pence reflects the absolute value of the company," he was quoted as saying.
Carlsberg has urged S&N shareholders to put pressure on the board to accept the proposed raised offer but said it would not launch a hostile bid for the brewer of Foster's and Kronenbourg, and the offer would lapse without a recommendation.
Van Boxmeer told the paper they were speaking to S&N shareholders and had received signs that at the current bid value investors were prepared to apply pressure.
The Financial Times reported on Friday a top 10 shareholder in S&N feared the brewer's intransigence would prompt the consortium to walk away, at which point S&N shares would collapse.
Asked whether Heineken was potentially paying too much for S&N's British operations van Boxmeer told Het Financieele Dagblad the Dutch brewer was maintaining its financial discipline.
"Market conditions in the United Kingdom were not good last year with the poor summer. But we are thinking long term. We are developing our premium Heineken brand and are outperforming the market," he said.
Heineken, the world's fourth-largest brewer in terms of sales, was not immediatley available to comment. Its shares closed down 3.2 percent at 42.32 euros on Thursday.
The bidding consortium faces a Jan. 21 deadline stipulated by the UK Takeover Panel to make a formal bid or walk away.