Complex sentence: In addition, Sea-Land Services, Inc. (an unrelated enterprise under Malcom McLean) had introduced containerized service to Puerto Rico in 1958, so to compete Seatrain Lines discontinued the transport of rail cars to Puerto Rico and utilized containers instead.
Split into simpler sentences: In addition, Sea-Land Service (an unrelated enterprise under Malcom McLean) had introduced containerized service to Puerto Rico in 1958. To compete Seatrain Lines discontinued the transport of rail cars to Puerto Rico and utilized containers instead.