Letter precedent to listing: conditions may be imposed and withdrawn for misrepresentation or material changes affecting listing. Regulation 12 authorises the Authority to grant a letter precedent to listing with conditions on disclosures and listings, to specify exchange(s), to require timely confirmation of compliance, to impose fresh conditions post grant, and to request information from applicants or intermediaries to verify compliance. Letters normally have a ninety day validity subject to discretionary extension. The Authority may withdraw a letter after affording an opportunity to be heard where terms change, material developments occur, material facts were suppressed or misrepresented, qualifications are no longer met, or withdrawal is in the larger interests of investors and the market.