And directors may have to be chaperoned by a third party when they meet outsiders.
These edicts are understood to be at the heart of the London Stock Exchange's completed guidelines on the dissemination of price-sensitive information.
The advice has been produced by a working party composed of Exchange officials and representatives of the Hundred Group of Finance Directors, the Association of British Insurers, the Institute of Investment Management and Research and the Institutional Fund Managers' Association.
The working party was set up last July, following widespread uncertainty after the Exchange censured the condom and rubber glove maker, London International Group, for telling a selection of analysts and institutional investors that their profit expectations for the year to March 1993 were too high.
In November, the working party published a consultative document recommending that listed companies should:
Plan investor communications.
Publish their communication policies.
Decide constitutes price-sensitive information.
Anticipate the likely impact of an announcement.
Consider announcing regular trading updates.
Waive close periods for announcements before a regular reporting event if the market needs information.
Michael Lawrence, the Exchange's chief executive formerly with the Prudential Corporation, said: 'Companies do not need a detailed code of practice, which would negate the professional judgement of directors and advisers, but they do need guidance to dispel uncertainties about what can be said and to whom.'Reuse content