Banks have steadily marched away from being all things to all people, and they are leaving tracks in M&A totals.

Many banks are sharpening their focus in the postcrisis operating environment by doubling down on niche services or shedding what no longer works. Nearly half of deal activity in the broader financial sector since 2011 involved divestitures, according to a new report from the Deloitte Center for Financial Services. That compares with 25.6% in the preceding decade, the global consulting firm says, citing Thomson Reuters data.

"For decades, many U.S. and global banks have been expanding their operations across geographies, business lines and customer groups," the report reads. "But the turmoil of the last few years has caused many banks to rethink this logic. Some firms have already begun to act."

The study's analysis is bent toward the largest banks, which are simplifying their organizations as part of the lessons learned from the 2008 financial meltdown, as well as in reaction to the onslaught of regulations that followed it.

"Higher capital requirements and more stringent risk-weighting rules have forced banks to make hard choices about where they compete," the report reads.

Deloitte highlights the specialization efforts of three large firms. It notes Citigroup's (NYSE: C) restructuring of its global network, including its exit from markets such as Turkey, Paraguay and Pakistan; Wells Fargo's (WFC) laser focus on mortgages, which has catapulted it in recent years to originating three out of every 10 mortgages in the United States; and UBS' departure from things such as fixed-income products and its refocus on private banking.

The authors were unavailable for comment on Monday. Still, other experts agreed that banks' quest for specialization through divestitures or acquisitions has been a major driver of M&A. Essentially, in the current low-rate and low-growth environment, banking has become a lot like a swap meet.

"For a while, we saw things like divestitures because banks were trying to survive. Now they are doing it as they look to figure out how they are going to prosper and to differentiate and overhaul their operations so that they can have a few business lines that they are really good at," says Terry Keating, a managing director at Amherst Partners, a financial advisory firm.

One of the most visible divestiture strategies has been Bank of America's (BAC) sale of scores of branches across the country as it looks to cut costs. The buyers have included: Arvest Bank, which bought nine branches in Arkansas; Old National Bancorp (ONB), which bought 24 branches in Indiana and Michigan; and Washington Federal (WAFD), which bought 51 branches in Idaho, Oregon, New Mexico and Washington.

"The reality is that in a world flush with liquidity, selling the branches that don't have sizable deposits or are not profitable operations becomes a logical decision," says Jeff K. Davis, a managing director of the Financial Institutions Group at Mercer Capital.

Additionally, acquisitive bankers in the Pacific Northwest spend the summer selling off peripheral branches to each other as they try to define themselves.

However, focusing sometimes means finding a business niche, rather than a geographic one. PacWest's (PACW) pending acquisition of the specialty finance company CapitalSource is an example of a bank starved for loan growth and finding it in a lender with a national focus. More deals like that are sure to follow as banks find it difficult to compete for traditional commercial credits in their existing markets, experts say.

"Trying to seek an edge in general commercial lending? That is pretty hard," Keating says.

Subscribe Now

Access to authoritative analysis and perspective and our data-driven report series.

14-Day Free Trial

No credit card required. Complete access to articles, breaking news and industry data.