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.

The deal has been closely watched and seen as a litmus test for how quickly the Trump administration will approve mergers in the financial sector.

Capital One's planned $35.3 billion acquisition of a rival credit card company, Discover, was approved by two regulators, Federal Reserve and the Office of the Comptroller of the Currency, on Friday.