FORT BRAGG, N.C. — The XVIII Airborne Corps no longer is in command of the 3rd Infantry Division at Fort Stewart, Ga., and in December won’t have the 101st Airborne Division under its command.

It’s all part of the Army’s continuing transformation, a post spokesman said Monday. The 3rd Infantry came from under the XVIII Airborne Corps on Sunday.

The changes will make the corps headquarters fit more neatly into the modular organization concept under which units are more independent and can be plugged into larger battle groups as needed around the world.

Transformation involves downsizing divisions of 10,000 ore more soldiers to smaller brigades of about 3,000 that can operate independently or be included under larger theater commands, like that in Iraq.

The corps “won’t have the responsibility of running the post as in the past,” said spokesman Col. Billy Bucker.

In the past, the commander of the corps has had four divisions under him as well as responsibility for all of Fort Bragg, one of the two largest Army posts in the country.

Now, the corps headquarters will be configured to deploy and become the command “module” of an army in the field and not have to worry about training the divisions at home. The corps headquarters and its former divisions will report to Forces Command, which is coming to Fort Bragg around 2010.

Eventually, the 82nd Airborne and 10th Mountain Division, located at Fort Drum, N.Y., will come from under the XVIII Airborne umbrella next year, Bucker said. At some point, the commander of the 82nd will be in charge of the post.

“The mission of XVIII Airborne Corps will change in that it will focus more on its primary warfighting mission,” said Lt. Gen. John R. Vines, commander of the XVIII Airborne Corps and Fort Bragg.

The XVIII Airborne Corps will be one of only three corps left in the Army by 2011. Already, the corps has disbanded and sent to other units its aviation brigade and is planning the same for its artillery, medical and communications commands.