Capital One-Discover Deal Hits Roadblock in Bank Merger Overhaul

New federal guidelines calling for stricter reviews of bank deals are likely to present fresh hurdles for Capital One Financial Corp.'s pending $35 billion acquisition of Discover Financial Services.

The tie-up, announced in February, would create the sixth-largest bank by assets and the largest credit card issuer in the US based on outstanding loans.

But a set of merger policies announced Sept. 17 by the Federal Deposit Insurance Corp., the Office of the Comptroller of the Currency, and the Justice Department’s antitrust division signal that federal regulators are ratcheting up their scrutiny of the deal, which has already been ...