By Nick Brown

NEW YORK, Nov 26 (Reuters) - A group of former MF Global customers on Monday asked a court for permission to subpoena the commodities broker's executives, including former CEO Jon Corzine, who was blamed in a congressional report this month for MF Global's collapse.

The Commodity Customer Coalition, an advocate for trader customers who lost money when MF Global went under, is seeking to subpoena Corzine, Chief Financial Officer Henri Steenkamp, Chief Operating Officer Bradley Abelow and others, according to court papers filed in the U.S. Bankruptcy Court in Manhattan.

While Corzine has stepped down, some executives remain at the company, assisting in its wind-down. Abelow, the highest-ranking executive still at the firm, just last week gave his notice and is leaving at the end of the week, a person familiar with the matter told Reuters on Monday.

MF Global went bankrupt in October 2011 after its heavy exposure to European sovereign debt spooked investors. The case has become a political firestorm as investigators in Congress and elsewhere try to identify the source of an estimated $1.6 billion hole in customer trading accounts.

Corzine's role has been unclear. James Giddens, the trustee liquidating MF's broker-dealer unit, said in a June report that Corzine failed to address growing liquidity needs as he built the firm into a global investment powerhouse.

Giddens said MF Global used customer funds to cover liquidity gaps as the firm teetered on the brink.

More recently, the Republican-controlled House Financial Services Committee put the blame squarely on Corzine, saying in a Nov. 15 report that he failed to maintain the controls necessary to protect customer funds.

Corzine, a former co-chairman of Goldman Sachs who also served as a Democratic U.S. senator and governor of New Jersey, has denied any wrongdoing.

Reuters reported in September that prosecutors are close to wrapping up a criminal inquiry and are unlikely to file criminal charges.

Some customers have sued Corzine for civil charges, including breaching fiduciary duty.

The coalition is also seeking to subpoena MF Global General Counsel Laurie Ferber and former Treasurer Edith O'Brien, as well as Christine Serwinski, former finance chief at MF's North American brokerage.

An attorney for O'Brien declined to comment. Lawyers for the other parties did not respond to requests for comment.

James Koutoulas, a fund manager who leads the coalition, on Monday told Reuters that Corzine should be forced to face questions from customers under oath.

A spokesman for Corzine declined to comment.

Judge Martin Glenn, who is overseeing MF Global's liquidation, in February denied a similar subpoena request from another former MF Global customer, saying it would impede ongoing investigations by authorities.

Many officials, including Giddens, the Department of Justice and the FBI, have been investigating the case and have spoken to MF Global executives.

Giddens' role -- to return as much money as possible to former customers -- raises questions as to whether granting the coalition subpoena power could be redundant.

Giddens has already returned to customers about 80 percent of the money in their accounts, which were frozen when the company went bankrupt. He has said he will try to recover much of the roughly $1.6 billion gap in those accounts through litigation or settlements with MF Global affiliates, regulators and counterparties.

Giddens has also joined forces with plaintiffs who have sued Corzine for alleged civil infractions.

Still, Koutoulas says customers should be able to take matters into their own hands and ask Corzine and fellow brass detailed questions about the firm's collapse.

"This case needs another kick in the butt," Koutoulas said. "It's almost like the courts are treating Corzine as a sacred cow that can't be touched."

Kent Jarrell, a spokesman for Giddens, declined to comment on the coalition's subpoena efforts. He said Giddens "stands by" his June report and will continue to cooperate with plaintiffs in civil lawsuits against Corzine.

(Additional reporting by Joseph Ax)

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