Requirements: B-1 in lieu of H-3

Trainee has nonimmigrant intent (foreign residence to which he or she must return)
Trainee must clearly be employed and paid by an overseas company
Training program is not designed primarily to provide productive employment
Training program is not available in the alien’s home country
Trainee will not be placed in a position that is normally occupied by U.S. workers
Any productive employment is only incidental and necessary to the training and pursuance of a career outside of the United States
Generally, training program is less than six months
Source:
 
9 FAM 41.53 N11.9; 9 FAM 41.53 N4.5; 8 C.F.R. 214.2(h)(7); U.S. State Department, B-1 in Lieu of H, Unclassified Cable 12 State 101466 (Oct. 12, 2012).