The Virginia House of Delegates narrowly approved a measure today that would allow 16 municipalities that now produce their own electrical power to join forces to finance new generating facilities and buy shares in existing power plants.

The controversial bill passed the House 51 to 48, but only after the legislation's harshest critics had succeeded in significantly amending the proposal and sending it back to an uncertain fate in the Senate.

Passage of the measure would allow municipalities with their own utility operations, among them Manassas and Culpeper, to, jointly or separately, create electric authorities to build their own generating plants that would sell the power they produce wholesale to the municipalities.

But the House voted to place this authority under the regulation of the State Corporation Commission after Del. Ray L. Garland (R-Roanoke City) called the bill "a horror story" that would give too much control to the municipal utility operations.

"It's a blank check for the localities to give these electric authorities anything they want," argued Garland, who complained the bill would set in motion a "trend... whose consequences we cannot predict."

Proponents of the bill said it had been studied for two years and was drafted so as to apply only to municipalities with existing electric operations.

In other Assembly action today, the Senate passed a House-approved measure requiring undertakers to provide itemized bills for funeral expenses. The vote was 23 to 15.

Opponents argued that the bill represents overregulation of a business governed by a regulatory agency, the Board of Funeral Directors and Embalmers. However, Sen. Clive L. DuVal II (D-Fairfax) said all seven members of that agency are in the funeral business and "can hardly be expected to pass this kind of regulation."

In elections in both houses to fill uncontested judgeships, General District Court Judge Lewis H. Griffith of Fairfax County was named to an eight-year term as Circuit Court judge in the county's 19th Judicial Circuit. He replaces Circuit Court Judge James Keith, who is retiring.

The Senate also approved a bill, 38 to 0, that authorize George Mason University to grant doctoral degrees.