A Commerce Department unit yesterday urged the Federal Communications Commission to authorize regional phone companies to ignore a ruling by federal judge Harold Greene that bars them from offering computer services, saying the step is needed "to ensure the country's competitive future in the 'information age' is not needlessly compromised."

The plea by the department's National Telecommunications and Information Administration was a new sign of frustration in parts of the phone industry and the Reagan administration over Greene's vast and continuing influence in the development of the nation's telecommunications network.

"A judicial bottleneck blocking the development of information services is neither mandated by competition or communications policy, nor sanctioned by existing law," NTIA chief Alfred C. Sikes said in a letter yesterday to FCC Chairman Dennis Patrick, urging him to take action.

"Judicial constraints have contributed to denying American consumers access to services that are readily available in an increasing number of countries overseas," Sikes wrote.

NTIA spokesman R.T. Gregg said the unit wants to create a legal conflict between the FCC and Greene's court that would be resolved by a federal appeals court.

The FCC last night gave a mixed response to the proposal.

"We are sympathetic with their position" against Greene's limits on computer services, said FCC spokeswoman Sally Lawrence. "We are not sure, however, that the approach articulated in their position is the correct one."

The proposal will be studied further, she said.

Greene, a judge in U.S. District Court in Washington, oversees the 1982 consent decree that settled a Justice Department antitrust suit against American Telephone & Telegraph Co. and broke up the giant company, creating the seven regional phone companies.

In September, as part of a review of implementation of the decree, Greene reaffirmed limits on the role the regional companies can play in the fast-growing data transmission business.

He said they could act as a pipeline for other companies' transmissions, but could not maintain data bases that would provide the information, lest this encourage them to monopolize the business.

Consumer groups and some competitors of the regional companies have supported Greene's stance.

The Justice Department, Commerce and the FCC, however, all favored lifting those limitations, as did the regional companies, to allow optimal development of the data transmission industry.

In his letter, Sikes said the FCC has a legal responsibility to ensure that the nation has modern and efficient communications services. He urged Patrick and the FCC to rule that the regional companies could enter the business.

Sikes said Greene's ruling would help raise the United States' trade deficit. Keeping the regional companies out of the information business will encourage the proliferation of "intelligent" terminal equipment, he said, and foreign-based firms have a large share of this market.