Wells Fargo unveiled a new credit card and is bolstering how it rewards customers for their spending, crucial steps in Chief Executive Officer Charlie Scharf's mission to make the fourth-largest U.S. bank a bigger player in a space long dominated by rivals.

Banks and trade groups denounced the Consumer Financial Protection Bureau's final rule to cut credit card late fees to $8, saying they will do everything possible to kill the rule.

The two companies in the largest bank merger since the 2008 financial crisis released details of their agreement. It leaves the door open for Discover to field better offers, though the payments company would pay a break-up fee of 4% if it accepts one.

In the wake of the largest U.S. bank deal in more than 15 years, industry executives offered mixed views about the prospects for more big acquisitions. They also spoke about the deal's impact on competition in the credit card business.

Lenders collected an estimated $25 billion in additional interest income last year by raising the average margin on annual percentage rates, or the amount above the prime rate, according to the Consumer Financial Protection Bureau.

The credit card lender's blockbuster acquisition of Discover is not guaranteed to get across the finish line. But co-founder and CEO Richard Fairbank appears to see the rewards that would come from controlling a payments network as outweighing the potential downside.

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.

Capital One Financial's proposed acquisition of Discover Financial Services would create a credit card behemoth with its own payments network. The deal is likely to draw tough regulatory scrutiny, though analysts say there are many compelling strategic reasons for the combination.