Baltimore Mayor William Donald Schaefer made his campaign for Maryland governor official yesterday on the steps of his West Baltimore row house, then moved to the classrooms of a Prince George's County school to say he would provide more money to improve elementary and secondary education.

Schaefer, 63, entered the race for the Democratic nomination citing the experience he has gained in 16 years as mayor of the state's largest city.

"My record shows that I know how to make government work," Schaefer said in Baltimore to applause from a group of about 400 supporters, most of them elected officials. "I have effectively managed an administration with an annual budget of over $1.5 billion and a work force of over 30,000 people. There is no other candidate for governor, Republican or Democrat, who can say that."

Schaefer, who enjoys a comfortable lead in the polls, will face Attorney General Stephen H. Sachs in September's Democratic primary. In Upper Marlboro and Baltimore yesterday, Schaefer renewed his criticism of Sachs' announced plan to raise money for education by increasing the state's 5 percent sales tax by one cent on the dollar. Schaefer has said the state already has enough money without such an increase.

Sachs questioned Schaefer's stated interest in education yesterday, given the condition of the financially strapped Baltimore schools.

"What the mayor has not learned in three terms plus is that education is more than public relations," said Sachs, an announced candidate for several months.

"You can get away with public relations on other issues and the neglect does not show as vividly. In order to improve education you have to do more than pat little children on the head. You have to make a commitment that in an election year he is not willing to make."

Schaefer met with Prince George's School Superintendent John A. Murphy, County Executive Parris Glendening and U.S. Rep. Steny Hoyer (D-Md.) at school headquarters in Upper Marlboro before leaving to take a walking tour of the extended day-care program at Kettering Elementary School.

Extended day care is part of the county's new magnet school program, begun this school year to provide an alternative to court-ordered busing plans that have failed to desegregate much of the school system. The before- and after-school care, paid for by parents, provides an incentive for working parents to keep their children in public schools, Murphy told Schaefer.

Schaefer said afterward that he was impressed with Murphy's plan. "Every place I've been, the first thing they sat down and said is we need more funds," Schaefer said. "Dr. Murphy talked first about accountability for the funds we already have."

If elected governor, Schaefer said, his administration will be "sympathetic" to requests for additional state support for programs such as the Prince George's magnet schools, which will receive $5.5 million in state funds this year.

"I can see where the money's going here," he said.

Earlier in Baltimore, Schaefer was joined by longtime companion Hilda Mae Snoops on his balloon-decorated front porch as he made his announcement to a gathering that included several potential running mates: state Del. Nancy K. Kopp (Montgomery), state Sen. Laurence Levitan (Montgomery), state Del. R. Clayton Mitchell Jr. (Kent), and state Sen. Catherine I. Riley (Harford).

Schaefer's attention to economic development will aid the state immeasurably, Levitan said. "His big thing is people, business and jobs. What the state needs most is someone who can go and aggressively sell the state."