Although "new town" ventures are in financial trouble around the country, Fairfax County may soon get its third start-from-scratch community.

Developers of the highly successful Burke Centre west of Springfield plan to build a smaller, but similar, town on an 840-acre farm in western Fairfax north of Rte. 50.

The town, which would eventually house 5,000 to 6,000 people, has already been named "Franklin," after the name of the family that has farmed the land.

"We're kind of paddling against the tide," said John T. Hazel Jr., the Fairfax zoning attorney who plans to build Franklin with his two Burke Centre partners, Milton V. Peterson and Guiseppe Cecchi, both veteran developers in metropolitan Washington.

The federal Housing and Urban Development Department recently shut down its new communities office, which lost $149 million in a decade of trying to control suburban sprawl with designed "new town" that offer housing with economic and racial mixes.

Reston, Fairfax's first new town, and Columbia, Md., both privately financed ventures, have survived, though not without some shaky periods.

Of the many towns that failed, Hazel said: "They all got enamored of large landholdings in outlying areas with no infrastructure of services."

Like Burke Centre, Franklin would be built on the edge of already-established suburban neighborhoods, Rte. 50 and I-66 - two major east-west roads - will be near Franklin and the proposed Springfield bypass, which would run north-south across the county, and would bisect the new town. The new Fair Oaks regional mall, now under construction at I-66 and Rte. 50, is a few miles away.

Hazel and his partners have applied for the special "planned residential community" zoning that would give them wide latitutde in how they could put their town together. If there are no major problems in getting the zoning, Hazel said construction could begin as early as late 1979 and be completed in five to seven years.

There would be single-family and town houses in the $65,000-to-$90,000 range, Hazel said, with neighborhoods connected by a trail system.

The motif would be the "down-home" look that was employed for Burke Centre, in southern Fairfax, whee house sales have been booming. Franklin's recreation and visitor center, which will be a focal point of the community, will be housed in the present Franklin family homstead.

Like Burke Centre, Franklin will be tailored to largely middle-class aspirations. There will be no subsidized housing for low-income or moderate income people.

While Franklin will not, be as ambitious as any of the new town experiments that attracted so much attention in the late 1960s and early 1970s, Hazel said it will be an attempt to bring order to an area that he said is an example of haphazard suburban planning.

"The zoning so far has been mostly sprawl," Hazel said. "We're going to try to put a center of focus in Franklin." It won't be sprawling."

Hazel said he and his partners acquired the land for about $6,500 an acre. At that price, the 840-acre tract would have cost close to $5.5 million.