Delta Air Lines is offering its traditional winter specials earlier than usual because of slow business in the travel industry.

"It looks like it's happened a little bit earlier now, which is telling me bookings are a little bit softer than expected," said Raymond E. Neidl, an airline analyst with Dillon Read & Co.Delta will award a free ticket to any frequent flier who completes four round trips or two round trips with plane changes on coach fares between Dec. 15 and March 15. The bonuses are redeemable between May 15 and Dec. 31, 1991.

The program also offers passengers first-class upgrades rather than free trips.

Airlines typically offer specials during the slow winter season, but the overall ill health of the industry prompted Delta to begin its promotion before the peak Christmas season ends, Delta spokesman Neil Monroe said.