Connecticut's banking commissioner announced yesterday that he will reopen a hearing on whether to suspend or revoke E. F. Hutton & Co.'s registrations to do business in that state as a broker-dealer and investment adviser.

Commissioner Brian J. Woolf will take testimony Aug. 12 in Hartford, granting a request by state Attorney General Joseph I. Lieberman. The request, in which Hutton has concurred, was triggered by Hutton's release of hitherto undisclosed documents.

The Connecticut case arose from Hutton's May 2 plea of guilty to 2,000 federal counts of mail and wire fraud in a check-kiting scheme in which numerous banks lost millions of dollars on unintended interest-free loans to Hutton. Like Connecticut, most states allow officials to fine or to suspend or cancel the license of a broker-dealer convicted of a felony.

Woolf held a hearing June 20 at which Hutton President Scott Pierce said employes who perpetrated the scheme engaged in "stupid activities which were bound to be discovered." Company witnesses also testified that the scheme involved no customer funds and broke no federal securities laws.

Hutton executives said at the time that the firm's senior management had no knowledge of or involvement in the illegal activities, and that when they learned of the practices, they issued directives to stop them and prevent their recurrence.

On July 10, the company disclosed that it had found and turned over to the federal government 18 additional documents covered by subpoenas issued by a federal grand jury and the House Judiciary subcommittee on crime. Hutton gave copies of the documents, some of which already had leaked to the press, to the Justice Department, the subcommittee and the SEC.

Five days later, Lieberman asked Woolf to reopen the hearing. The 18 documents, which Hutton has turned over to the state, "have been characterized by various media sources as indicating that some members of senior management encouraged or were aware of excessive overdrafting of regional bank accounts to increase interest income for" Hutton, Lieberman said.

In asking to reopen the hearing, Lieberman said he wanted "to determine senior management's involvement, if any, in the illegal activity; to test the veracity of the testimony" given by Hutton representatives on June 20, and "to gauge the degree to which the respondent has rehabilitated itself."

The Justice Department has said that no executives were involved and that the scheme was the work of two low-level employes. By not bringing criminal charges against them, the department said, it was able to win Hutton's consent to a trail-blazing civil agreement to make full restitution to the banks and to refrain from abusive cash-management practices not covered by the felony charges. The company is setting aside $8 million as a reserve for restitution.

Hutton has five of its more than 400 branch offices in Connecticut; they handle more than $100 million in assets for clients.