Prudential was forced to abandon plans to publish details of its US$21 billion ($29 billion) rights issue this morning, says The Times of UK.

The insurer had encountered last-minute regulatory issues with the Financial Services Authority over its planned US$35.5 billion acquisition of AIA in Asia.

Prudential cancelled a telephone call with journalists minutes before it was due to take place at 7.30am and failed to publish its prospectus for the rights issue on the regulatory news service at 7am. The Pru may now not publish the prospectus today.

The Pru is hoping to tap its shareholders to part-fund its US$35.5 billion acquisition of AIA in Asia.

However, there has been much disquiet among investors about the deal, for which many believe the Pru is overpaying. Some have wanted the Pru to reduce the size of the rights issue by finding other ways to raise money, such as by selling businesses.