NEW YORK – The Occupy Wall Street movement has led many banks to hire extra security. Manhattan’s Amalgamated Bank has rolled out the red carpet.

The bank, owned by the Workers United labor union, has emerged as the unofficial financial institution of the anti-Wall Street movement.

Even people who hate banks, it seems, need a bank.

“It was quite obvious we were not going to open a Bank of America account,” said Wylie Stecklow, who serves on Occupy Wall Street’s finance committee. “But we had to deal with banks if we were going to process funds.”

Amalgamated is where the Occupy Wall Street movement has about $326,000 in donations deposited, or about two-thirds of the total raised by the New York arm of the movement, according to its finance committee. When things have heated up, as they did when protesters were temporarily evicted early this week, the bank has provided support, including storage space, conference rooms and advice.

But even banks trying to change the world get drawn into the less attractive corners of Wall Street. Amalgamated made some controversial investments in California subprime mortgages and recently gave a 40 percent ownership stake to some of the same private equity titans that Occupy Wall Street has been protesting against.

“First and foremost the bank has to be a bank, and has to be and should be a successful bank,” said the bank’s chairman, Noel Beasley, who is also the head of the Workers United union.

Ed Grebow, the bank’s chief executive, is a former private equity manager himself, coming to the bank from J.C. Flowers & Co., a global private equity firm run by billionaire investment banker Chris Flowers.

More recently, though, Grebow has been on the streets of New York protesting during marches aimed at denouncing the banking industry.

“I’m trying to show personally that you can be a bank, but also be supportive of progressive values,” Grebow said.

The tension between upholding progressive ideals and operating in a world mesmerized by money has been a growing issue for Occupy Wall Street. It has come up in the movement’s incongruous effort to trademark its name, and in debates about accepting donations from business leaders.

In California, the Oakland, Calif., encampment confronted the contradictions when it begrudgingly deposited $20,000 in a mega bank — Wells Fargo & Co. — while it waited for a credit union account to open.

But these tensions are brought into particular focus at Amalgamated. Founded by the Amalgamated Clothing Workers of America in 1923, the bank has a long history of trying to bridge the chasm between capitalism and labor.

In the early days, the bank existed to provide services to immigrant workers whom other banks avoided. Amalgamated has continued to cater to those customers, with things such as free checking accounts and branches in working-class neighborhoods.

The bank has grown to 27 retail branches focused mostly in New York, with other locations in Pasadena, Calif.; Las Vegas; and Washington.

Grebow says with each of the bank’s operations there is a careful effort to support only projects that its union partners would agree with.

“We talk a lot about what we need to do to be a bank that has good business practices,” he said.

When the protesters on Occupy Wall Street’s finance committee journeyed to meet Grebow at the bank’s midtown headquarters, they liked what they saw.

“He’s a very regular dude,” said Pete Dutro, who is one of the members of the committee that is handling the movement’s money.