The Chicago White Sox and expansion Arizona Diamondbacks are to made it official Friday: they'll join the Colorado Rockies in spring training in Tucson.

The White Sox, one of baseball's oldest franchises, and the Diamondbacks, which won't begin major league play until 1998, will share a $25 million complex at Kino Veterans Memorial Sports Park starting in 1998.

Both teams will commit to training in Tucson for at least 15 years, the minimum sought by the Pima County Board of Supervisors.

Earlier this year, the Denver-based Rockies agreed to stay at Hi Corbett Field, where they've trained since 1993, for 15 years on two conditions: that the stadium, built in 1927, undergo another $3.4 million in renovations, and that two more major league teams agree to train here.

-The Associated Press