Despite a Tuesday morning fire that caused $250,000 worth of damage to its backstage dressing room area, the Merriweather Post Pavilion expects to open its 12th season on schedule in early June.

The fire, which Howard County fire officials have declared to be of suspicious origin, occurred on the first anniversary of the fire that destroyed the Filene Center at Wolf Trap Farm Park in Vienna. However, the Pavilion, privately owned by the Nederlander Organization, is fully insured, while the federally owned Wolf Trap was not.

Tuesday's fire was confined to the backstage area and, according to Pavilion spokesman Charles Blum, fire-retardant wood kept the flames from spreading.

"Once it was spotted, it was contained until the firemen could get there," Blum said. "We're beginning repairs the middle of next week, and we'll be going on as scheduled."

During the summer, the Pavilion is the largest producer of concerts in the metropolitan area. Last year, 60 concerts attracted close to half-a-million people. The Pavilion has 5,000 covered seats, and lawn seating for another 5,000. Yesterday, 35 concerts were announced. The opening concert has not been announced, but there is a strong possibility that it will involve the Beach Boys. Another early possibility is Bob Seger, who is confirmed but without a set date; his current tour ends in June.

The 1983 schedule: Shirley Bassey (June 24), Rick Springfield (June 27), Bette Midler (June 30, July 1), Moody Blues (July 2), Eric Clapton (July 5), Pat Metheny (July 8), Air Supply (July 12), Barry Manilow (July 15, 16), Hall and Oates (July 18), Linda Ronstadt (July 19, 20), Joni Mitchell (July 22), The Osmonds (July 24), Jackson Browne (July 25), John Denver (July 27), Peter, Paul and Mary (July 29), Peter Gabriel (July 30), Tom Jones (Aug. 4), Paul Anka (Aug. 7), Kenny Loggins (Aug. 8), Loverboy (Aug. 11), Melissa Manchester and David Brenner (Aug. 12), George Benson (Aug. 13), Asia (Aug. 14), Elvis Costello (Aug. 16), Charlie Daniels (Aug. 18), Al Jarreau (Aug. 19), Sheena Easton (Aug. 20), Roberta Flack and Peabo Bryson (Aug. 26) and James Taylor (Aug. 30). Other confirmed concerts without set dates will feature the Little River Band and a jazz package headed by guitarist Al Dimeola.

The Pavilion season usually runs through Labor Day weekend.