NEW YORK (Reuters) - Former U.S. Securities and Exchange Commission Chairman William Donaldson on Wednesday said the United States needs a regulatory overhaul, similar to changes made to the system after the Great Depression.

“It’s clear there have been some regulatory breakdowns,” Donaldson said at a CFA Institute conference in New York.

“As we move forward, the structures need to be changed ... we have to have really serious examinations of our regulatory institutions and their mandates.”

Donaldson, who was chairman of the SEC from 2003 through 2005, said the current market turmoil should result in careful changes being made to the system as the structure of U.S. markets has changed drastically since the main U.S. securities law, the Securities Exchange Act of 1934, was put into effect.

“As demand for regulation increases, which it is and will, I think we really have to figure out the structure,” Donaldson said. “The institutions of regulation ... these were all products of the 1929 crash and depression.”

In that era it “was easy to tell what is a bank,” Donaldson said, but new and more creative areas of financing have changed that.

For example, the credit crisis has brought billions in government support to financial companies that were not traditional banks, like investment bank Bear Stearns, insurer American International Group and mortgage finance companies Fannie Mae and Freddie Mac.

After the $85 billion bailout of AIG this week, Donaldson said the insurance industry was ripe for a new kind of regulation.

“One of the longer term problems, if you will, is the insurance industry being regulated by state regulators,” Donaldson said. ” It’s a long-term situation, very difficult to change, but I think any sort of reorganization has to bring some new thoughts on how to coordinate the regulation of that industry.”

However, Donaldson suggested any overhaul should be pursued after the political tensions from the U.S. presidential election have passed.