Capital One cleared the final hurdle in acquiring Discover, which would merge the two US credit card giants. Federal regulators approved the deal, which is expected to close on May 18, Capital One announced Friday in a press release.

Capital One and Discover are set to merge and will soon be the largest credit card issuer in the U.S. On Friday, the Federal Reserve announced that it had approved Capital One Financial's application to acquire Discover Financial Services.

Two regulators signed off on the $35 billion deal, which the banks say will create a competitor to Visa and Mastercard. But consumer advocates warn that the deal may raise costs.