Bankers feel more optimistic about their business as crisis memories fade, and more open-minded about M&A as deal prices rise, but concerns about compliance challenges and regulators' tough reviews of merger applications are keeping their enthusiasm in check.

Banks and other companies headquartered abroad have been busy buying and selling financial firms in the United States recently. Here's a look at M&A activity lately that's had a distinctly international flavor.

Southern First Bancshares (SFST) in Greenville, S.C., used a private placement to convert preferred stock tied to the Troubled Asset Relief Program into common stock.

The Los Angeles company had to negotiate with the government, private equity, nonprofits and other banks to recapitalize its bank.

NBT Bancorp (NBTB) in Norwich, N.Y., reported fourth-quarter net income of $17.9 million, a 37% increase from a year earlier.

FirstMerit (FMER) in Akron, Ohio, announced a substantial increase in net income because of its April purchase of Citizens Republic Bancorp in Flint, Mich.

Institutions with solid, but underperforming assets and lagging stock price valuation multiples are vulnerable to activist investors. Address problems before they are attracted to your bank.

The global M&A market in 2013 was solid across all sectors, according to a report by advisory firm Greenberg Advisors.

The $300 million merger will create the state's biggest community bank -- and could convince other institutions to pursue similar deals.

A breakdown of M&A announcements in the financial services industry for the week ended Jan. 25.

Bank of Montreal is in talks to buy F&C Asset Management Plc, manager of the oldest U.K. investment fund, for about 697 million pounds ($1.2 billion) in what would be the second-largest takeover in its 196-year history.

A number of community banks have removed CEOs, announced plans to sell or reached compromises with dissident shareholders in recent weeks. And proxy season has yet to hit its stride.

Hanmi Financial (HAFC) in Los Angeles reported dip in quarterly profits because of costs related to its planned acquisition of Central Bancorp.

A new accounting framework could give banks a leg up in small-business lending by making it cheaper for companies to provide accurate financials, but accounting experts are divided over whether the standards are an improvement or risky and confusing.

VantageSouth Bancshares (VSB) in Raleigh, N.C., and Yadkin Financial (YDKN) in Elkin, N.C., are merging.

The Oklahoma State Banking Department has closed Bank of Union in El Reno.

The Mississippi bank's latest acquisition would take it into the Austin, Texas, market, but CEO Dan Rollins refuses to answer questions from investors and analysts about how quickly it would earn back its dilution of tangible book value.

CEO Gary Crosby believes new technology will help the Buffalo, N.Y., company generate revenue more in line with being a large financial institution. But his $250 million investment pledge didn't sit well with investors who were hoping for cost-cutting.