A two-mode, compound-split, electra-mechanical transmission utilizes an input member for receiving power from an engine, and an output member for delivering power from the transmission. First and second motor / generators are operatively connected to an energy storage device through a control for interchanging electrical power among the storage device, the first motor / generator and the second motor / generator. The transmission employs three planetary gear sets. Each planetary gear arrangement utilizes first, second and third gear members. Moreover, one gear member of the first or second planetary gear set is operatively connected to the input member, and one gear member of the third planetary gear set is selectively connected to ground. A lock-up clutch selectively locks two of the planetary gear sets in a 1:1 ratio.