A small community bank in New Hampshire found a demand from its regulator last month just too much.


Monadnock Community Bank in Peterborough was ordered to do a thorough review of how it collected payments on its delinquent loans, said William Pierce, the chief executive. That meant diverting three of its 18 employees to comb through reams of mortgages.


“We’ve had two foreclosures in the last four years, and yet here we had to do it anyway because our regulator only knows how to deal with the behemoth banks,” said Mr. Pierce, referring to the regulator, the Office of the Comptroller of the Currency.


Frustrated, Mr. Pierce agreed to sell his institution, which has $82 million in assets and a charter as a savings and loan association, to the GFA Federal Credit Union in Gardner, Mass., a credit union overseen by the National Credit Union Association — not the comptroller’s office.


An increasing number of the nation’s more than 600 savings and loan associations are fleeing the comptroller’s office as they navigate a shifting regulatory landscape. The Dodd-Frank financial reform law closed their longtime regulator, the Office of Thrift Supervision, and moved them to the comptroller. A few of these institutions are trying to become credit unions, and many others are choosing state oversight. Nationally, 35 have applied to switch from national to state charters since July 2011.


While the banks say that they are looking for a regulatory agency that understands them, some former industry experts have expressed concern that the financial institutions are regulator shopping.


The Office of Thrift Supervision was a notoriously easy supervisor, said James Gilkeson, a former regulator at the comptroller’s office. “Going to state and credit union regulators is clearly a search for the next best thing,” he said.


Banks are displaying a familiar pattern, Mr. Gilkeson said. After each financial crisis, lawmakers try to buttress regulation by closing a weak supervisor and consolidating oversight under a stronger central agency. Then many banks, faced with a new regulator, try to find more lenient supervision. In the late 1980s, because of the savings and loan crisis, the Federal Home Loan Bank Board was closed and the new Office of Thrift Supervision, he said, was going to be the “big muscle.”


The latest migration is getting bank regulators’ attention. “We are dealing with a false perception that the O.C.C. doesn’t understand community banks,” said Jennifer Kelly, senior deputy comptroller for midsize bank supervision in the office.


The agency says it is committed to local regulation. As an example, it points to its team of 207 midsize or community bank examiners in Texas alone.


Still, New York has seen an uptick in applications from nationally chartered banks that want to be overseen by the state, according to Benjamin M. Lawsky, the New York superintendent of financial services.


Community bankers vociferously deny that they are hunting for lax regulators. What they want, they say, is a regulator more in touch with the issues faced by the nation’s smaller banks, which are different from the ones faced by their larger national counterparts. “The O.C.C. basically punishes the community banks as if we committed the sins of risky lending that the biggest banks did,” Mr. Pierce said.


No one disputes that regulators allowed banks to distribute risky loans to subprime borrowers, among other dubious practices, leading up to the financial crisis. But some community bankers say that the tighter regulation that has resulted has gone too far and should be focused more on the nation’s largest banks. Even though their capital requirements are different from those of the biggest banks, the smaller banks say that requirements for loan-loss reserves, for example, are depleting them of capital that could be otherwise used for loans.


Despite their complaints, small banks were not immune from the financial crisis. This year, 16 community banks, which have up to $10 billion in assets, have failed. The pace of bank failures is slowing, though. Last year, 92 community banks failed. 


 To get a new regulator, banks have two options under state and federal banking laws. They can become a credit union — either through a charter conversion or through an acquisition, as Mr. Pierce’s bank did — or they can convert to a state charter.