A civil rights group is accusing Sinclair Broadcast Group of trying to "corruptly influence" Maryland's recent gubernatorial election by illegally providing free helicopter service for Gov.-elect Robert L. Ehrlich Jr. and then attempting to cover it up.

In a motion filed with the Federal Communications Commission, attorneys for the Rainbow/ PUSH Coalition said the Baltimore County-based broadcasting firm engaged in fraud by failing to disclose to its local viewers that it had an "economic interest" in one of the candidates.

The 35-page brief was submitted Monday to support a pending motion by Rainbow/PUSH to get the FCC to reverse its approval of Sinclair's purchase of 14 television stations, including WNUV-TV in Baltimore. That purchase is also the subject of a pending federal court appeal.

Spokesmen for Ehrlich and Sinclair Broadcast dismissed the accusations as baseless.

Pointing to "newly discovered evidence of disqualifying misconduct," the civil rights group is asking the commission to reopen the case and hold hearings to determine whether the sale approval should be overturned.

"These matters are so serious that they place starkly at issue Sinclair's qualifications to hold any broadcast licenses," the brief states.

Citing several recent newspaper stories disclosing that Ehrlich was provided with the use of a luxury helicopter owned by a company with ties to Sinclair's majority owners, the group said the company billed for use of the aircraft only after questions were raised by reporters.

"Even then [the] bills were fabrications," the brief states.

The group also said that Sinclair was behind a campaign to have ex parte letters sent by three congressmen, including Ehrlich, in an attempt to improperly influence the federal panel in the same case. An FCC attorney subsequently chided Ehrlich for writing the letter without notifying other parties to the case.

Yesterday, Ehrlich spokesman Henry Fawell called the Rainbow/PUSH charges "meaningless" and said they had nothing to do with "issues of importance" to Maryland residents.

Fawell also defended Ehrlich's letters on Sinclair's behalf, calling them "standard constituent work. It's what hundreds of members of Congress do on a daily basis."

"On behalf of a constituent, all he did was inquire about the status of a constituent case," Fawell said.

Mark Hyman, Sinclair's vice president for corporate and government relations, denied that his firm played any role in the letter-writing campaign. He said then-Rep. Steve Largent of Oklahoma had taken the initiative on the campaign.

Hyman characterized the latest Rainbow/PUSH filing as "a desperation effort by a group unsuccessful in its shakedown efforts."

The remark was an allusion to allegations, endorsed by Sinclair officials, that the Rev. Jesse L. Jackson and other coalition leaders demand consulting contracts and other financial arrangements from broadcasting companies. By this account, the coalition's officials threaten to block actions that require FCC approval if they do not receive such benefits.

Ehrlich and Largent both mentioned Jackson in their letters to the FCC, and promised to launch a congressional inquiry if "political" considerations were found to have caused any delay in the approval process. In Baltimore, Sinclair owns WBFF-TV, and it is seeking to purchase WNUV, which it manages for an out-of-town owner with close links to the family of Sinclair Chief Executive Officer David D. Smith.

The accusations made by the civil rights group this week focus on recent disclosures that Ehrlich made several campaign trips on a luxury helicopter owned by Whirlwind Aviation. Records show the helicopter firm is headed by a member of the Smith family, which holds a controlling interest in Sinclair.

As The Sun reported, the helicopter rides were not reported by Ehrlich's campaign committee until after the initial press inquiries. Whirlwind then billed the committee at the rate of $1,000 an hour, less than half of what the firm normally charges.

Subsequently, the Ehrlich campaign announced that it would pay the standard rate - $2,450 an hour, for a total of $34,300. That figure will be reduced, however, by $7,700, which has now been designated as in-kind contributions by Whirlwind to the campaign committees of Ehrlich and his running mate, Michael S. Steele.

"Sinclair Broadcast Group apparently attempted to corrupt the most important election Maryland has had in four years," the brief states. "The helicopter flights were attributable to Sinclair since they were provided to candidate Ehrlich through what the Ehrlich campaign and the candidate himself understood to be Sinclair's initiative."

It cites some contributions by members of the Smith family, which controls Sinclair, to Ehrlich's campaign, and says: "The public fundamentally deserved to know of Sinclair's hidden interest in candidate Ehrlich in order to decide itself whether to trust Sinclair's on-air coverage."

The filing by Washington lawyer David Honig asserts that "Sinclair made secret contributions in order to corruptly influence the Maryland gubernatorial election."

Pointing to what it called Sinclair's "campaign of lawlessness," the group argues that the new evidence of misconduct by the broadcast firm "more than justifies starting over and doing it right this time."

Sun staff writer David Nitkin contributed to this article.