Kevin Spacey stars in first-time director J.C. Chandor's "Margin Call," a drama set in a New York bank as it scrambles to offload massive toxic debts irrespective of what it means for the market or the population as a whole.

Spacey, as long-serving trading boss Sam, wrestles with the knowledge that his actions will harm the bank's reputation and put people out of work, but he, like others in a cast including Demi Moore, feels obliged to follow orders as that is what pays.

Chandor said the movie, which has its premiere at the Berlin film festival on Friday where it is in the main competition, sought to humanize the world of big-bonus banks and to show that greed went further than the world of finance.

"What the script for me is about is not excessive greed on any one individual's part, but it was the greed on a very small scale of the whole population, certainly in the United States," he told reporters after the official press screening.

Spacey said he welcomed the opportunity to explore what it was like for people caught in the center of the financial crash in 2008.

"There was a period of time where you couldn't pick up a newspaper and not read that every banker was the most horrible and greedy person that walked the face of the earth," the Oscar-winning actor told a news conference.

"The truth is ... in a lot of cases, these are regular people who have regular jobs who aren't making gazillions of dollars and who have to follow orders, and that's the crux of the morality of the piece and why I found it so fascinating."

MASS SACKINGS, DARK HUMOUR

Set over a 24 hour period, Margin Call opens with mass layoffs that are handled with almost comic brutality.

Who goes and who stays seems arbitrary, phone accounts are shut down the minute a person is sacked, and the newly unemployed are frog-marched out of the building clutching cardboard boxes containing their personal effects.

A young analyst, played by Zachary Quinto, is passed an electronic file by his outgoing mentor, and he soon discovers that it contains the bank's dirty secret -- that it is sitting on billions of dollars of almost worthless assets.

Academy Award winner Jeremy Irons plays the ruthless boss, who is called in to the swanky Manhattan offices in the middle of the night for an emergency board meeting where he must decide how best to save the bank from going under.

The actor said he believed all big business was amoral, including the movie industry, as it was driven only by profit.

"The problem is that to live in a world which is self-continuing we need morality," Irons said.

"We have to care about the fact that people are having their houses taken away from them.

"My role was an amoral man who just wanted to keep the ship afloat ... because that was his job, but we have to add something else to the mix. I think that has to be morality."

Asked how the financial crisis had affected the movie business, Spacey said it had made independent film-making even more of a challenge than it used to be.

"I wish and hope that we could return to the days when the major studios had arms for independent films," he said.

"I wish they'd take some of the proceeds (from lucrative blockbuster franchises) and make 10 great small films about stories that ... need to be told."

For Chandor, Margin Call was part thriller and part tragedy, because the investment banks had succeeded in recruiting so many of the brightest young people from around the world.

"It's just people you're seeing ... realizing that they've wasted a little bit of their lives or a lot of their lives and, more importantly, their time."