The CEO of MF Global, Jon Corzine, told U.S. lawmakers Thursday he doesn’t know the location of clients’ money that disappeared when the company failed.

Testifying before the U.S. of Representatives’ Agriculture Committee later Thursday, Corzine said that he inherited a company that was on a failing course.

The collapse of MF Global on Oct. 31 has raised questions about the adequacy of regulatory oversight of trading in the massive global commodities market.

"I am devastated by the impact on many people's lives" of the failure, Corzine said, adding he accepts responsibility for the firm's risky bets, and its customers' losses weigh on his mind "every day — every hour."

The former U.S. senator has been subpoenaed to explain how the firm, which he led for about 20 months, became the eighth-largest bankruptcy in U.S. history and why an estimated $1.2 billion US in client funds is unaccounted for.

Agricultural businesses use brokerage firms such as MF Global to help reduce their risks in an industry vulnerable to swings in oil, corn and other commodity prices.

When asked directly why clients' funds were not kept separate from money used by the firm itself, Corzine pleaded ignorance.

"I want to emphasize that, since my resignation from MF Global on November 3, 2011, I have not had access to the information that I would need to understand what happened," he said.

"It is extremely difficult for me to reconstruct the events that occurred during the chaotic days and the last hours leading up to the bankruptcy filing."

But under Corzine’s leadership, the firm increased risks by making big bets on European government debt — bets that proved disastrous.

Some of the lawmakers before whom Corzine testified have heard from farmers, ranchers and small business owners in their districts who are missing money deposited with the firm.

Canadians had $400M on account

Canadian clients had about $400 million Cdn on account at MF Global Canada Co. On Nov. 14, an Ontario court approved a move by bankruptcy trustee KPMG to transfer of most of the money to RBC Dominion Securities.

Corzine, 64, apologized to "all those affected" by MF Global's failure. He hasn't spoken publicly until today.

"I simply do not know where the money is, or why the accounts have not been reconciled to date," Corzine said.

He said he can't say whether there were "operational errors" at MF Global or whether banks or other companies have held onto funds that should be returned to MF Global.

Corzine said many in his position would invoke their rights under the U.S. Constitution to avoid incriminating themselves and refuse to testify, but said that as a former senator, he recognizes the importance of congressional oversight and will try his best to answer the panel's questions.

Testifying poses risks

A Democrat, Corzine represented New Jersey in the U.S. Senate from 2001 through 2005. He later served as the state's governor.

Before entering politics, he was CEO of Wall Street investment bank Goldman Sachs from 1994 to 1999.

Testifying poses risks for Corzine. What he says could be used in court should he ever be charged.

The FBI and several federal regulators are investigating MF Global.

Corzine said the company's revenue was "drying up" when he arrived because of competition from online and high-tech brokerages.

The amount of borrowed money used — known as leverage — decreased when he ran the company, he says, and he favoured the trades that doomed it only after discussions with MF Global's senior traders.

Corzine notes that the European debt securities are all "at least A rated." Typically, that means the borrower is unlikely to default.

Janet Tavakoli, an expert on the transactions MF Global specialized in, said Corzine's remarks divert attention from the firm's fundamental flaw: It lacked the cash to cover its bets after investors started to fear that a major European nation would default.

"His entire testimony looks like a very skilled way to try to detract from that key issue," said Tavakoli, president of Tavakoli Structured Finance.

With files from The Associated Press