Space-Time block codes (STBC) from Orthogonal Designs (OD), Quasi-Orthogonal Designs (QOD) and Co-ordinate Interleaved Orthogonal Designs (CIOD) have been attracting wider attention due to their amenability for fast (single-symbol decoding for OD, CIOD and double-symbol decoding for QOD) ML decoding, and rate-one with full-rank over quasi-static fading channels [1]-[13]. The importance of CIOD is due to the fact that, rate-one, full-rank, square ODs for arbitrary complex constellations exist only for 2 transmit antennas while such a CIOD exists for 2,3 and 4 transmit antennas with a slight restriction on the complex constellations [12], [13]. These limitations motivate study of rectangular (non-square) designs. One way of obtaining rectangular designs is by deleting columns from square or non-square ODs or CIODs. In this paper, we present a new construction of rectangular single-symbol decodable designs that have higher maximum mutual information than those obtained by deleting columns of CIODs and has lower peak to average power ratio (PAPR). Simulation results are presented for three and five transmit antennas and compared with that of OD, QODs, CIODs to demonstrate the superiority of the proposed rectangular designs.