Computer giant Apple is facing a major class action in the latest episode of the backdating share options scandal that has hit more than 150 US companies and an unprecedented number of corporate counsel.

The New York City Employees Retirement System pension scheme, which holds $90m (£45m) worth of shares in Apple, was last week appointed as the lead claimant in a class action. The shareholders are demanding compensation for what they allege were illegally-issued stock options.