Despite objections from some Fairfax County legislators, the Virginia General Assembly moved toward agreement today on proposals to settle the state's often-bitter annexation and revenue-sharing disputes.

It is the third successive year that the assembly has wrestled with legislation aimed at ending annexation wars between cities and counties. The bills would bring an end to annexation of counties by cities and provide more state revenue for all local governments, especially the cities that would be prohibited from expanding by annexations.

The House of Delegates Appropriations Committee approved a key part of the package today. It would provide $151 million in new funds -- $30.5 million of it for Northern Virginia -- in the state's next two-year budget for the years 1980-82.

The Senate Transportation Committee approved another key element of the package, a new formula for allocating state highway money, but it did so over the opposition of Sens. Omer L. Hirst (D-Fairfax) and Charles L. Waddell (D-Loudoun). Hirst and Waddell, whose district also includes western Fairfax County, objected to the new formula because it would reduce highway construction funds for Fairfax by an estimated $1.5 to $2 million a year.

Hirst suggested in an interview that his proposed treatment of Fairfax could cause him to withdraw support for the annexation package. Failure to hold together competing regional interests has been fatal to the package in each of the last two years.

The roads "proposal by itself is not good for Fairfax County," Hirst said. "I'm compassionate about mud roads in Southwest Virginia and inequities for cities, but I'm not prepared for Fairfax to bear brunt of helping them."

The reduction in road aid for Fairfax results from an effort to shift a greater share of $670 million a year in state highway money to rural secondary roads and city streets.

Senators from other urban counties, also hurt by the new allocation, supported the measure because they want immunity from annexation by adjoining cities. Hirst said Fairfax does not have this incentive, because "the last unsuccessful annexation suit against us by Alexandria put those fears to rest."

In other action, the Senate unanimously approved a bill pledging state backing to $57 million in revenue bonds to build a four-lane commuter toll road parallel to the Dulles Airport access road.

The Senate also approved a Waddell bill, 33 to 2, that would require auto repair shops to give estimates of repair costs to customers, who would have a right to refuse to pay costs that surpass estimates by more than 10 percent. The bill is a weakened version of stringent repair shop regulations proposed in recent sessions.

In other action, the House gave tentative approval today to a bill that would exempt church-operated daycare centers from most state health and safety regulations. The measure, which provoked much debate in committee and on the House floor, would still require minimal inspections by local fire and health authorities.

Additionally, a House committee to day approved 9 to 6 a bill sponsored by women delegates that would more clearly establish judicial guidelines in divorce cases.

Del. Gladys Keating (D-Fairfax), one of the sponsors, said the bill establishes the concept of marital property and the rights and interests of each party, husband and wife, to share in such property regardless of monetary contributions to the marriage.

The measure would set up separate provisions dealing with degrees of support and maintenance for spouses and children, custody and division of property within court jurisdiction.

Keating said current law on the subject of divorce is very brief and very vague and allows judges too much discretion in the distribution of property and custody cases.