Nearly a third of all new homes being built in Montgomery County next year will be financed with the help of mortgage revenue bonds issued by the county Housing Opportunities Commission, the agency announced.

The bonds enable the county to offer low- and moderate-income persons financing for new homes at below-market rates, slightly higher than 13 percent. The commission estimates that about 1,300 families will buy homes with the $65 million in mortgages financed through the sale of the bonds.

In addition, the county hopes to give a boost to 24 local construction firms to which the mortgage money has been allocated. The companies are to use the funds for homes costing no more than $65,000 at any of 31 new subdivisions they are building in the county.

Most of the developers also are "buying down" the mortgages for the first four years, and 15 local lenders are participating in the program.

The commission at a meeting earlier this month raised the income limit for eligible families. The new limits range from $27,900 for a one-person household to $35,900 for families of six or more.

Persons wishing to participate are advised to go to the sales office of the development in which they want to buy.

The new communities involved in the program are:

Middlebrook Condos in Gaithersburg (Ryan Homes), Quail Ridge in Gaithersburg (Ryan Homes), Greencastle in Colesville (Capital Homes), Gunners View in Gaithersburg (Ryan Homes), Picton in Montgomery Village (Kettler), Farmingdale in Germantown (Porten Sullivan), The Oaks in Silver Spring (Brisker-Campitelli), Avonshire in Colesville (St. Charles Homes), Hunter's Woods in Gaithersburg (Design Collection), Parcel HRB in Germantown (Pulte), Woodlake in Germantown (U.S. Home), Nathan's Hill Montgomery Village (Kettler), Middlebrook Townhouses in Gaithersburg (Ryan Homes), Stone Bridge Meadow in Damascus (Ja Laur), Churchill in Germantown (Pulte), Damascus Manor in Damascus (Ryan Homes), Flower Hill in Gaithersburg (Pettit & Griffin), Montgomery West in Gaithersburg (Ryan Homes), Cashell in Olney (Pulte), Waters Landing in Germantown (Ryland Group), Overlea Montgomery Village (Kettler), Green Hills in Damascus (Design Collection), Sweepstakes in Damascus (Damascus Land Corp.), Gilbert Subdivision in Silver Spring (Avery-Flaherty), Greens of Warther in Gaithersburg (Miller & Smith), Heritage Gate in Germantown (Bresler & Reiner), Downing Square in Germantown (Sparta Brook), Gaithersburg City (John duFeif), Pheasant's Run in Gaithersburg (Pulte), Mineral Springs in Gaithersburg (Pulte).