A special committee of United Technology Corp. directors is investigating charges that company Chairman Harry J. Gray wiretapped the home and office of former UTC president Robert J. Carlson, who had been considered the next in line to Gray until he resigned in September.

The company yesterday confirmed that an investigation was under way, but provided few other details. The Wall Street Journal made the investigation public in a story yesterday, saying that Carlson had accused Gray of bugging his home and office. The Journal said the directors' panel is also investigating whether former UTC executive vice president Edward L. Hennessy Jr., who, like Carlson, was considered a possible successor to Gray, was wiretapped by the chairman.

The committee is expected to report on its findings shortly, the company said, but so far has found no evidence of wrongdoing. A company spokesman would not say whether the Federal Bureau of Investigation or other law enforcement agencies are also investigating the charges, but Bernard Feeney, assistant special agent in charge of the FBI office in New Haven, Conn., said the bureau was attempting to contact Carlson as a result of the Journal story.

Gray denied the allegations in a statement issued by the company, saying, "The allegations are completely false and I am confident the report will confirm this. This company has not, and will not, engage in any activites that are illegal or unethical."

Neither Carlson nor Hennessy, who resigned in 1977 and is now chairman of Allied Corp., could be reached for comment. Critics have said that Gray forced out his possible heirs so that he could retain control of the company. Gray has denied those assertions.

The three directors conducting the investigation -- Robert Dee, chairman of SmithKline Beckman Corp.; Robert Malott, chairman of FMC Corp.; and Darwin Smith, chairman of Kimberly-Clark Corp. -- could not be reached for comment. Attempts to reach other directors also were unavailing.

One director, former Treasury Secretary William E. Simon, was quoted by the Journal as saying, "The intrigue up there is just unreal -- it's like a James Bond novel."

The bizarre allegations fed an already tense situation at United Technologies, the nation's 16th-largest industrial company and a major Pentagon supplier through its Sikorsky helicopter and Pratt & Whitney jet-engine divisions. The company's stock, which had dipped when Carlson resigned, yesterday dropped $1.625 to $37.75 in active trading.

Gray, who will turn 65 later this month, has reportedly resisted the board's requests that he retire at that time, and is currently serving without a contract at the pleasure of the board. He is expected to stay on at least through the first part of next year, while a successor, apparently UTC's new president, Robert Daniell, is groomed for the position.

The last four possible successors to Gray's post, including Carlson, Hennessy, and former secretary of State Alexander Haig, either have been fired or resigned from the company. Haig could not be reached for comment yesterday.

UTC said the investigation began Sept. 18, the day after Carlson's resignation. The company statement said Gray had requested the investigation, but Carlson's attorney, Harvey Myerson, said yesterday that the former president -- who is still a UTC director -- had asked the board to look into the charges.

According to The Journal, Carlson became suspicious after a series of break-ins at his home in Avon, Conn., not far from UTC's Hartford, Conn. headquarters. Myerson said Carlson's home had been broken into three times, and The Journal said Carlson believes that the motive was to install and remove listening devices. No one has been arrested in connection with those break-ins.

A source familiar with the case said Carlson's office at UTC's headquarters was vandalized on the day he left the company, with light-switch plates removed and furniture slit open. "It was pretty evident when wall plates have been taken off and small slits have been made in precise places that somebody is retrieving something," The Associated Press quoted a source close to the investigation as saying.

The Journal reported that United Technologies security personnel had electronically swept Carlson's home and office for listening devices and found nothing.

According to The Journal, Hennessy has told associates that he believed the UTC security department had bugged his office and telephone when he was with the company.