RICHMOND, DEC. 15 -- A panel of Virginia legislators, responding to growing demand for affordable child day care, endorsed a new system of subsidies today to give low- and moderate-income parents greater flexibility in selecting day care facilities for their children.

The subsidies, based on government-backed vouchers, will likely be tested soon in three pilot programs around the state -- one in an urban setting, another in a suburban jurisdiction and a third in a rural county, according to legislators.

Although other states have had mixed results with such day care subsidies, Gov. Gerald L. Baliles is expected to ask the General Assembly next month to earmark as much as $12 million to pay for a voucher system if the three pilot programs are successful, one of his Cabinet secretaries said today.

"People are demanding day care now just like they demanded public schools in the 1800s," said state Del. David G. Brickley (D-Prince William), chairman of a joint state House-Senate subcommittee that has studied day care issues for most of this year. Government-sponsored vouchers, he added, "would keep one segment of Virginia off welfare but allow them to have free choice in selecting the best day care for their children."

In contrast to the state's current day care reimbursement system, a fee-based structure that frequently channels children to inexpensive and sometimes inadequate programs, a voucher system would permit families to take advantage of more expensive and in some cases better-run day care centers, voucher advocates said.

At a time when some jurisdictions have limited their daily reimbursments to a few dollars -- Richmond's, for instance, is $5 -- a paper voucher from the state would be a kind of ticket to help working parents send their child to a facility they might not otherwise be able to afford, advocates said. After accepting a child, the day care facility would turn in the voucher to the state government, which would then reimburse the day care center for its services.

Under the system being contemplated for Virginia, only licensed or state-certified day care facilities would be eligible to participate in the voucher program, state officials said.

Eva S. Teig, the state's secretary of human resources, told Brickley's committee that a voucher system was one way to begin "leveling the playing field" between competing private, profit-oriented day care centers and nonprofit care programs that often receive an array of government subsidies.

"Vouchers mean increased availability of day care for parents who work," said Teig, who noted that some jurisdictions, notably Fairfax County and Alexandria, already have "stable and comprehensive" child care systems.

In a related development at its meeting here, Brickley's committee voted to require state government agencies that are establishing in-house day care centers to contract out those programs to private day care providers. Brickley said the requirement would help redress the "disadvantage" that private centers have in competing against subsidized facilities.

Meanwhile, the state Department of Transportation has announced it will include a child care center for 40 children as part of its expansion to an office building in downtown Richmond. The decision was based on a survey showing that many of the department's 1,600 employes thought a day care center located near their office was "a great idea," a spokeswoman said.