President Reagan will ask Congress to appropriate the federal share of a $5 billion program to combat acid rain, the White House said yesterday.

A statement by presidential spokesman Marlin Fitzwater also said Reagan has accepted the recommendations of a task force that called for eliminating regulatory barriers to development of "innovative emissions control technologies."

These steps, Fitzwater said, would be in keeping with commitments Reagan made to the Canadian government, which is concerned about acid rain pollution from the United States.

"The president has instructed his advisers to continue discussions with their Canadian counterparts toward completion of a bilateral air quality accord," the statement said. "He reiterated his commitment to implement the recommendations" of a 1986 report by special U.S. and Canadian envoys.

Reagan indicated earlier he supported a five-year, $5 billion federal and industry effort to encourage development and deployment of systems to reduce power plant emissions thought to cause acid rain.

The statement said the president will request the full federal share of the program, $2.5 billion.

The recommendations of the president's Task Force on Regulatory Relief are aimed at speeding development of new emission controls. Among the recommendations:Give preferential regulatory treatment to states that, for the purpose of setting utility rates, treat innovative technologies the same as other pollution control projects. The Federal Energy Regulatory Commission should give greater leeway to utilities to foster development of new methods against acid rain.