Fairfax County School Superintendent Robert R. Spillane, one of the top contenders for the chief education post in Texas, said yesterday that he has dropped out of the running and plans to stay in Fairfax.

Spillane, who in 5 1/2 years at the helm of the Washington area's largest school district has earned a national reputation as an innovator, had been scheduled for an 8:30 a.m. interview with the Texas Board of Education yesterday for the post of state education commissioner.

However, he said he called the state's search firm on Friday to withdraw his name.

"There's a lot left here to finish, and I just felt it was not in my or the district's interest to pursue it further," he said. "You have to finish one operation before you head on to another one. I don't think it is {finished} yet."

As head of the 130,000-student district, Spillane attracted national attention by starting a teacher merit pay program that has earned applause from some educators, parents and business leaders but has drawn considerable criticism from local teacher unions and cost-conscious politicians.

Spillane also has championed lengthening the school day. He added a half-hour and a seventh class period in secondary schools last fall and has proposed extending Mondays to a full day for elementary schools beginning in September.

His insistence this month on reviving the Monday plan, even after it was rejected by the School Board, irritated several board members, union leaders and PTA activists.

Spillane, who was the runner-up for the chancellorship of New York City schools in 1989, said money was not a factor in his decision. The retiring Texas commissioner, W.N. Kirby, is paid $116,590, $40 a year more than Spillane receives in Fairfax.

Spillane was one of five out-of-state educators on the list of eight finalists.