Gov. Charles S. Robb has proposed a $25 million plan to eliminate the persistent vestiges of segregation on Virginia's public college campuses, revising and strengthening a four-year-old program that the federal government declared a failure earlier this summer.

The new plan, released two weeks after it was submitted to the Education Department's Office of Civil Rights for review, would give Virginia another five years to comply with a federal desegregation mandate issued in 1969.

By 1988, Virginia proposes to increase black enrollment at the state's 13 predominantly white four-year colleges by 1,500 students, according to state Education Secretary John Casteen III.

Casteen said he was optimistic that the new plan would be accepted by the federal agency, but he also cautioned that problems left by the state's once-segregated college system would be difficult to eradicate.

"I am not going to assert to anybody that we have a solution that will solve a problem no state has solved," Casteen said at an afternoon press conference.

The new plan, which must be funded by the General Assembly, outlines several new statewide efforts designed to increase the number of black students entering college and to improve the caliber of education offered at Virginia State University and Norfolk State University, two traditionally black colleges.

The new plan would provide$1,000-a-year grants to blacks transferring from community colleges to finish their junior and senior years at the state's four-year predominantly white colleges. Similar grants would be available to whites who transfer to the historically black colleges. This program, expected to cost $2.9 million during three years, is an expanded version of a program that offered students a one-time-only grant of $1,000.

The plan's overall $25 million price tag could pose a problem, some legislators predicted today, particularly in light of Robb's recent orders for a cutback in state spending.

"When every college is dealing with a 5 percent cut due to circumstances of the economy, what are you going to do when you ask for. . . new programs?" said Senate Majority Leader Hunter B. Andrews (D-Hampton). "Certainly, it is quite a problem."

Components of the plan drew praise from some legislative leaders. "It's more than an appearance of compliance," said state Sen. L. Douglas Wilder (D-Richmond), the state's leading black elected official. "They are not just coming up with a placebo."

The Robb plan replaces a 1978 document drafted by then governor John N. Dalton, who broke with his conservative supporters and agreed to negotiate "numerical goals" for integrating the colleges. By last year, only two of the state's 13 traditionally white colleges had met their black enrollment goals. This summer, some of those same colleges reported an actual decline in black enrollment.

In contrast to the Dalton plan, the Robb proposal attempts a broader attack at the causes of de facto segregation at Virginia colleges. In particular, it stresses efforts to increase the number of black high school students applying to colleges, correcting a gap that many said caused the Dalton plan to fail.

Casteen has argued that the solution lies with giving blacks a better preparatory education in the public schools. A recent University of Virginia study showed that only 40 percent of black high school students who wanted to go to college were enrolled in appropriate courses.

To deal with that problem, the new plan includes a $250,000-a-year request for the printing and distribution of booklets and classroom charts informing students of their educational choices. It would start, says Casteen, with a booklet to be given to parents "when their babies leave the hospital.

"Parents have to know right up front from the start what the whole character of educationis," Casteen said today. "What kind of nursery schools are available, and so on. It addresses family involvement in this."

Other elements of the plan include:

* A $100,000-a-year program to attract white professors to Virginia State and Norfolk State universities. That program would include salary supplements, relocation allowances, and other bonuses to entice in-state professors at traditionally white schools to transfer to the black schools.

* A $500,000 program for creating a pool of 10 visiting professors to be composed of "nationally distinguished" scholars who would agree to teach at one of the black schools.

* A wide-ranging series of "enhancement" actions at the black schools, including $6.2 million for the completion of construction of buildings at the two institutions, and $250,000 a year to boost administrators' salaries and increase their budgets for printing, mailing, travel and consulting services.

* An estimated $80,000 a year for consultants to help implement the plan.