Online marketplace eBay has rejected an offer from GameStop to buy the company for $55.5 billion, dealing a blow to the video game retailer’s ambitions to create a rival to Amazon.

After reviewing GameStop’s proposition, the eBay board had concluded that the proposal was “neither credible nor attractive,” eBay board chairman Paul Pressler wrote in a letter to GameStop CEO Ryan Cohen Tuesday. In the letter, which was shared with CNN, Pressler said the board had taken the decision after considering eBay’s “standalone prospects,” the “uncertainty” regarding how the deal would be funded and GameStop’s “governance and executive incentives,” among other factors.