Stream Control Transmission Protocol (SCTP) specifications utilize the multiple paths capabilities between the sender and receiver for retransmission of lost data chunks and as a backup in case of primary path failure. Under normal conditions, all data chunks are sent on the primary path chosen by the SCTP user during the transport connection initiation. In this paper, we address in detail various aspects related to extending and engineering SCTP in order to utilize the available paths for simultaneous transmission of data chunks, while maintaining the SCTP congestion control on each path so as to ensure fair integration with other traffic in the network. The extended SCTP, referred to as Load-Sharing SCTP (LS-SCTP), is able to aggregate the bandwidth of all the active transmission paths between the communicating endpoints. LS-SCTP monitors the paths, and accordingly it chooses the paths that are suitable for load sharing. LS-SCTP retransmission mechanism accelerates the delivery of missing data to the receiver in order to prevent stalling the transport connection while waiting for missing data chunks. Simulation results show that LS-SCTP is extremely beneficial for networks with limited bandwidth, high loss rate and failure prone links.