This research investigates coordination of multiple mobile manipulators for grasping and transporting large and irregularly shaped objects. A mobile manipulator considered in this study is composed of a mobile platform for locomotion and a manipulator for grasping and manipulation. A large object without special features such as handles cannot easily be grasped by the conventional end effectors such as jaw grippers or multifingered hands. A new approach based on the concept of enveloping grasp and manipulation by multiple mobile manipulators is proposed. The major contribution of the proposed study will be control algorithms for coordination of locomotion and manipulation of a mobile manipulator with the motion of the manipulator being constrained, and coordination of two mobile manipulators for transporting large objects. An experimental system will be developed to test and evaluate the proposed coordination algorithms. //