The process of selecting a firm to receive Montgomery County's lucrative cable television franchise moved a step further last night as the county's cable project manager and a citizens' advisory panel selected a top group of competing firms.

Project manager John Hansman released a report showing the firm of Montgomery Cable Communications Inc./Times-Mirror Cable Television scoring 100 percent in his analysis. It was followed by VIACOM Cablevision of Maryland Inc. and Tribune-United Cable of Montgomery County, both with 99 percent. Eight companies are competing for the franchise.

The county's Cable Television Advisory Commission, a group of 13 citizens selected by County Executive Charles W. Gilchrist and approved by the County Council, selected four firms as top ranked after failing to reach a consensus on recommending only one firm.

Tribune-United finished first in the committee's rankings, followed closely by MCCI/Times-Mirror, VIACOM and First County Cable.

Hansman must now review the committee's selections before giving a final list of firms to Gilchrist, who then will pick a firm in late August.

MCCI/Times-Mirror is a joint venture of a firm whose local board chairman is R. Robert Linowes, a prominent Montgomery lawyer, and the company that operates The Los Angeles Times Newspaper. Tribune-United also is a joint venture, involving the firm that operates The Chicago Tribune.

Previously, Carl Pilnick, the county's independent cable consultant, had released rankings that showed six of the eight firms within four percentage points of each other. Last night's scores from Hansman showed a preference for three.

"Times-Mirror has no major weaknesses," said Hansman. "They are the most generous in terms of community programming. Their institutional network is very strong."

Hansman said that he thought that VIACOM had "the best operating plan . . . with more modest construction costs," adding that Tribune-United's strengths are its proposal to wire the entire county and its reasonable rates.

Initially, the citizen panel was asked to vote on selecting one firm, and in that ballot Times-Mirror received no votes, prompting one committee member to say, "We are going to have difficulty justifying this." Both Hansman and Pilnick ranked Times-Mirror highest.

Instead, the committee voted to recommend four firms and then the 12 voting members ranked four by preference. The meeting was attended by several representatives of the firms, including Abe Pollin, owner of the Washington basketball Bullets and ice hockey Capitals, who is one of the principals involved in First County Cable.