Senate Majority Leader Chuck Schumer, D-N.Y., said that he would like to examine the proposed acquisition on "narrower bases."

First National has agreed to buy Touchstone Bankshares. The combined company would have more than $500 million each of deposits and loans.

Bank mergers and acquisitions have slowed in recent years amid recession fears and other economic uncertainties. But bank consolidation is a century-old trend that's expected to rev up again as early as this year due to higher costs, tougher regulation and fierce competition.

Rocket shrunk its workforce by about 20% year-over-year, while Academy cut 250 employees prior to being acquired by Guild Mortgage.

Rep. Maxine Waters, ranking member of the House Financial Services Committee, led the letter, spurred by the recent merger announcement between Capital One and Discover, which the letter said would enable the merged company "to influence multiple points of the marketplace."

The lawmakers, led by Sen. Elizabeth Warren, D-Mass., said the deal would further anti-consumer bank consolidation, but also criticized the OCC's proposed changes to the merger process, asking that they be strengthened.

The blockbuster merger proposal will be reviewed at a time when the Biden administration is expressing skepticism about consolidation. Its analysis will have to account for markets dominated by both big banks and the likes of Visa and Mastercard.

The deal involving Southern California Bancorp and California BanCorp, expected to close in the third quarter, would form a $4.6 billion-asset lender with a footprint spanning San Diego, Greater Los Angeles and the San Francisco Bay Area.

Banks began marketing the loan, which funded a 47% stake purchase in Everise in early November. But the sale for the B3 rated debt struggled and dragged on for over a month. 

In a deal arranged by the Federal Deposit Insurance Corp., the Pittsburgh bank has bought a portfolio from the wreckage of Signature Bank. The purchase should help PNC expand its fund banking business, which helps private equity firms manage liquidity and finance investments in the short term.