Mark Whitacre, the Archer Daniels Midland Co. executive who acted as an informant for the Federal Bureau of Investigation, expressed regret over his role in the antitrust probe that involves his company, according to interviews with local media.

''I would say, that if I did it all over again, I probably would have done it differently, instead of doing what I did 3 1/2 years ago," Mr. Whitacre told WAND-TV in Decatur, Ill., according to a transcript of the interview. "I probably would have left the company instead of doing this."In interviews Thursday with the Decatur Herald & Review, WAND-TV and other local media, Mr. Whitacre, president of Archer Daniels' Bioproducts Division, declined to comment on the investigation or on the company. He did admit, however, to being the FBI informant in the probe.

"This has not been easy for myself or my family," he told the Herald & Review. "To be an FBI informant has been a very stressful time for the family. Not just these past three or four weeks, but for the last several years."

Mr. Whitacre reportedly went to federal investigators in 1992 with concerns about his own company, which led to a probe of possible price collusion in the industry.

Earlier this month, Archer Daniels said a federal grand jury in Chicago was conducting an investigation into possible violations of antitrust laws in the food additives industry, specifically citric acid, high fructose corn syrup and lysine, a feed additive.

Among the companies that received subpoenas for documents and testimony in the probe were Archer Daniels, CPC International Inc., Cargill Inc. and the A.E. Staley unit of Tate & Lyle.

No charges have been filed in the probe, which is believed to be looking into possible incidents of price fixing.

Archer Daniels, which has said it is cooperating fully with authorities, vowed to defend itself against shareholder lawsuits stemming from the probe.

Three suits have been filed against the company and certain officials - two in Chicago and one in Delaware.

Mr. Whitacre is still on Archer Daniels' payroll as an employee, but has been on vacation. Asked if he would return to Archer Daniels' corporate offices, Mr. Whitacre told the Herald & Review, "That depends on a lot of factors."

He did not elaborate.