(Reuters) - GameStop's shares slumped more than 18% before the bell on Wednesday, as the brick-and-mortar video game retailer reported a decline in fourth-quarter revenue on the back of a spending slowdown and rising competition from e-commerce firms.

The Grapevine, Texas-based company also said late on Tuesday that it had cut an unspecified number of jobs, joining Japan's Sony and Electronic Arts in a bid to reduce costs as economic uncertainty hits discretionary spending.