Stephen Schwarzman, the chairman of the Blackstone Group, one of the largest private equity funds in the world, has compared US President Barack Obama's tax hike proposal to the Nazi invasion of Poland.

Addressing board members of a non-profit organization about the current US administration’s plans to raise taxes paid by the private equity industry, Mr Schwarzman said, "It's a war. It's like when Hitler invaded Poland in 1939."

The statement has earned sharp criticism.

In an e-mailed statement to financial news service DealBooks, Elan Steinberg, vice president of the American Gathering of Jewish Holocaust Survivors, wrote: “For the victims of Hitler’s Germany such insensitive remarks trivialize their suffering and cheapen public discourse. Mr Schwarzman, shame on you — find a better way to save on your taxes.”

Mr Schwarzman later apologized for his choice of word in an interview with the New York Post, but maintained his original point.

"I apologize for what was an inappropriate analogy," he said. "However, the fundamental issue of the administration's need to work productively with business for the benefit of the overall economy is still of very serious concern, not only to me, but also to large parts of the business community," he added.

The issue stems from the US government’s proposal that private equity firms should pay ordinary income tax rates on their compensatory share of profits, termed “carried interest.”

Those profits are currently taxed at 15 percent, and in the future could be subject to a 35 percent tax rate. The proposal, which could raise an estimated $24 billion, is only one part of the Obama administration’s broad $1.9 trillion tax increase proposal.

According to Forbes, Mr Schwarzman himself is worth $4.7 billion, making him one of America's richest citizens. The Blackstone Group posted a net income of $723 million in 2009.