Apple's legal troubles over its alleged stock options backdating are just beginning. A report todays says that the company is being sued by a shareholder who claims Apple granted four executives stock options the day before Microsoft's investment in the company was announced.

The executives were apparently offered 1 million shares of Apple stock just a day before Steve Jobs announced the Microsoft deal, which resulted in shares rocketing up 33%.

The four executives are named as Fred Anderson, former Chief Financial Officer; Guerrino de Luca, Executive VP of Marketing; Robert Calderoni, Controller; and Jonathan Rubinstein, Senior VP of hardware engineering.

With regard to the previous investigation into stock option backdating, Anderson and former general counsel and board secretary Nancy Heinen have not been cleared by the probe, although Jobs has been cleared of wrongdoing.

The most recent lawsuit, according to the Los Angeles Times, alleges that “improper timing of options was common at Apple Computer for years”.