Like other powerful hedge fund managers, Christopher Hohn is rarely in public view.

That may be why, waiting to testify in a courtroom in Manhattan, he sat on a bench with his eyes closed for quite some time.

Even in this zen-like state, Hohn, 40, the founder of the $11 billion London-based hedge fund, The Children's Investment Fund, or TCI, appeared intense, with his dark, angular features and black suit.

No wonder. He is a ferocious shareholder activist, known for rattling the cages of many corporate chieftains. The son of working-class Jamaican parents who immigrated to Britain, Hohn ignited the biggest takeover battle in banking ever, the $100 billion war for ABN Amro last year. In 2005, TCI succeeded in forcing the ouster of Werner Seifert, the chief executive of Deutsche Borse. Afterward, in his memoir, Invasion of the Locusts, Seifert painted Hohn as an arrogant and strange loner, driven by power more than greed.

"If one were to give him Gummi bears instead of money, he would probably be happy," Seifert wrote.

Today, Hohn was in the federal district court to testify in his own defense today against claims brought by the railway company CSX Corp., which accuses TCI and another hedge fund of violating securities regulations by accumulating undisclosed voting power for a proxy contest to unseat corporate management.

It was, he told this reporter, his first time in a courtroom, "anywhere, in my life."

Among CSX's allegations is that TCI formed a "group" with another hedge fund, 3G Capital Partners, to wage a proxy contest, long before the December 12, 2007, when the two funds say they formed such a group.

In questioning Hohn, CSX's lawyer, Rory Millson of Cravath, Swaine & Moore, cited a February 13, 2007 email from Hohn to Snehal Amin, his underling at TCI, saying that "increased activity" in CSX credit default swaps has "caused excitement in the stock," and, telling Amin, "I want to also discuss our friend Alex of Brazil." (Alexander Behring of 3G.)

The 3G fund happened to start buying CSX shares at that time, and Behring testified earlier in the day that it was all a "coincidence." Hohn insisted to Millson that the email about his "friend in Brazil" had nothing at all to do with CSX, but rather related to another subject in the email --- a company called Arcelor Brazil, in which TCI has been an activist investor.

"That's what you're telling me," Millson harrumphed.

Hohn said he speaks with Behring, who is a TCI investor, about once a month, and that he spoke with him that January about TCI's letter to investors on its "very large holding in U.S. transportation." Behring asked whether that meant the railway sector, and Hohn told him yes, and that CSX was one of those holdings.

Hohn began every conversation with Behring by noting "we are not a group," a line that Millson suggested was cynical attempt to get around the securities regulations. Millson saved his biggest cannon fire for TCI's swap relationship with Austin Friars, a hedge fund owned by Deutsche Bank, suggesting that relationship would influence how the bank would vote its CSX shares.

"We hoped but did not know how they would vote," Hohn said.

In the end, the judge may have had the most pointed questions: He suggested to Hohn that TCI was happy to have some funds, such as 3G "front run" its position in stock, and pressed Hohn on whether TCI could have filed a disclosure with the Securities and Exchange Commission showing it had an "economic" position through swaps contracts with Deutsche and Citigroup, but also "disclaim any beneficial ownership of shares."

"I wasn't aware of that," Hohn said haltingly, looking seemingly worried that the clubby world in which he told a select few to invest in CSX while keeping his swaps positions hidden from the rest of the world might be a real problem.

During a break in testimony, Hohn paced the courtroom, and looked over the shoulder of the court stenographer, making sure the spelling of his last name was correct.

"I'm just trying to be helpful," he offered,

Karen Donovan