A generalized O(2,1) expansion in the space-space region

Following the approach of Jones, Low and Young, a generalized O(2, 1) expansion is developed for amplitudes that have a power bounded growth asymptotically. The expansion, set up in an O(1, 1) basis, holds in a new kinematical region, where all the incoming and outgoing clusters have space-like O(2, 1) momenta.