"Whilst we didn't think there was a situation where there was currently an issue, we wanted to make sure we got our views across," Campbell said.
"What we are saying to people is, 'Here are some good practices around the use of alternative performance measures'."
Campbell said issuers of securities should be thinking about whether they were masking bad news by presenting certain figures and ensure the information they provided was consistent across different reporting periods.
"It's really all about good investor communication."
Campbell said if companies were to issue misleading information the FMA would get in touch by letter or a face-to-face interview.
"We can't remove a director's discretion around what is important information and we don't want to. We want directors to make those calls."
But she said the FMA wanted to see companies reporting the statutory measures alongside the alternative measures and explaining how it got between the two.
The guidance will apply to prospectuses, merger proposal documents and market communications including director or management commentary, market announcements, presentations to investors and briefings to analysts.
Campbell said the note not only covered listed companies but any entity which raised money from the public including charitable entities and public benefit entities.
Ernst and Young audit partner Kimberley Crook said the introduction of international financial reporting standards (IFRS) had been one driver in more companies using alternative measures as had one-off events such as the Canterbury earthquakes.
"People are wanting to isolate those figures because they hope it won't happen again."
Submissions on the document close on June 29 and the final guidance will be published by August 31.
The guidance will apply from January.