TUCSON - Tucson Open organizers are working on a deal which would make the early-season tournament the third Chrysler-sponsored event on the PGA Tour and a participant in a lucrative bonus pool by the auto manufacturer.

''We're negotiating, but it looks very good,'' said Boyd Drachman, co-chairman of the sponsor search committee for the Tucson Conquistadores, the tournament's support group.

Chrysler backs the Greater Greensboro Classic and the Bob Hope Classic. If it adds Tucson, Chrysler would ask the tour's policy board to approve a bonus pool that would pay a contestant $5 million for winning all three tournaments in the same year.

Two of the three titles would be worth $3 million.

Should each tournament produce a different champion, the bonus would be determined by a point system - one point for every dollar earned in the three tournaments. The player with the highest total would receive $500,000, said Ken Laurence, Chrysler's national advertising manager.

''You could win the series and not win one of the tournaments,'' Laurence said.

The Tucson Open has had two corporate sponsors - Seiko Time Corp. from 1984-87, and Nortel, which ended its relationship in January.