The UK’s Financial Services Authority has issued a warning to companies over their use of tailor-made profit figures, acting on concerns that some groups are in danger of confusing investors with their results.

International accounting standards allow companies to report additional earnings numbers that are not mandated in the rules, but many groups have chosen to highlight figures whose origins are vague. In the latest edition of its newsletter for listed companies, the City watchdog said yesterday: “[Companies] should make clear the basis on which such numbers are calculated in order to avoid misleading investors.”