A federal judge has certified a class action ERISA suit against Comcast Corp. in which employees of the cable television giant claim they suffered losses in the company stock fund because it was heavily invested in Comcast stock during a period when its price was falsely inflated.

At the heart of the suit are accusations that Comcast executives made overly optimistic predictions about the company’s growth in early 2007, driving the price of the stock up, despite being aware of market forces that were sure to result in significantly lower growth.