A federal judge today delayed for two months the opening of a major antitrust suit against American Telephone and Telegraph Co. after a newspaper article quoted the judge as calling AT&T's approach to the case "grandiose."

The quote was taken directly from a public pretrial order in the case by U.S. District JUDGE john F. Graydy. The case was brought by MCI Communications Corp. against the phone company, charging a monopolization of the business and data communications market.

Grady said the statement, published today in the Chicago Sun-Times, "appears to be an impediment to the selection of an impartial jury."

Grady, who has been praised for getting the case to trial, plans to try the case one month at a time. during the interim, he plans to keep up with his other trial work.

In a pretrial order filed last week Grady called MCI's list of 17 likely witnesses "an efficient presentation of its evidence."

But he also wrote that a reading of AT&T's witness list and proposed testimony "persuades me that the defendants have been thinking more in terms of a theatrical production than the trial of a lawsuit." "It is almost an understatement to say that defendant's approach to the case is grandiose."

Lawyers for both AT&T and MCI expected to begin selecting a jury today, as the five-year-old case came to trial. Opening statements were expected to begin late today.