A spokesman said the rumours had been circulating in the City over the past week and concerned Ladbroke's relationship with its banks and circumstances leading to the recent retirement of Cyril Stein, its long-serving chairman.
'Normally we do not take much notice of rumours about the company, but these were entirely false and particularly scurrilous,' he said. He added that the company was not planning to make any formal statement about the issue.
The warning letters followed an court injunction served by Mischon de Reya, Ladbroke's solicitors, on The Mail on Sunday, preventing the newspaper from publishing the allegations.
The moves come at a time when Ladbroke is under strain with its pounds 1.3bn debt mountain and difficult trading conditions in the property sector, and a price war in Britain's DIY products market.
In the past six weeks, the company's shares have slumped by about 15 per cent to close at 188p last Friday. Some market observers blame the drop on the rumours.
Last month the company reported a fall in taxable profits from pounds 84.4m to pounds 62.5m for the half year to 30 June. The result partly reflected a tripling of its interest bill to pounds 39m.
The interim dividend was maintained at 4.92p from earnings down from 4.73p to 3.98p per share. Several City analysts doubt whether the company can afford to hold its total payout for the year.
Mr Stein, who build up Ladbroke over the past 37 years, has been succeeded by John Jackson as non-executive chairman and Peter George as chief executive. Mr Stein will remain a non-executive board member for another three years.