In light of an appellate court action Monday, Montgomery County will seek a court order directing a Silver Spring landlord to pay almost $200,000 in rent rebates to tenants at the Colesville Towers apartment complex.

The Maryland Court of Special Appeals turned down the request of Lawrence Brandt building owner for an order that would force a rehearing before the county landlord-tenant commission. At issue was a 1974 rent increase by Brandt that the commission maintained was illegal.

In 1974 Montgomery County was still imposing rent controls, and the commission had denied Brandt's request for a 7 percent rent increase at a time when the county was allowing only 3 percent.

The Circuit Court later upheld the commission's decision. After the commission turned down Brandt's request for rehearing, Brandt took the case to the Court of Special Appeals.

Over the past four years, while the case was in litigation, Brandt was permitted to collect rents at the increased rate. Brandt is now liable to the tenants in the 11-story luxury high-rise at 8811 Colesville Rd. for almost $200,000, according to Assistant County Attorney Daniel P. Cassidy.

William Chen, Brandt's lawyer, said, "We are disappointed and dismayed by the decision." He said he and his client are considering appealing the ruling in the Maryland highest court, the Court of Appeals.

Chen said he has filed suit in U.S. District Court in Baltimore alleging that the commission violated his client's constitutional rights in denying his request for a rehearing.

Marilyn Wisoff, a tenant in the apartment complex, said of the Maryland appeals court's decision, "I'm ecstatic. It proves that what we fought for since September 1974 has been right and just . . ."