OSSINING, N.Y., Nov. 14 -- RSoft Inc. and Network Design Tools Inc. (NDTI) announced they have agreed to merge, creating a privately-held company that combines RSoft's physical-layer design tools with network-layer planning and optimization tools from NDTI, a Telcordia Technologies spin-out. The new company will supply researchers, manufacturers, systems integrators and service providers with performance, optimization, modeling and simulation (POMS) software that addresses design challenges from the component to the network level. Gail Lalk, NDTI president, has been named the acting CEO of the combined company and will retain her position as president of the network-layer products division. LuAnn Scarmozzino will continue as president of the physical-layer products division, and Robert Scarmozzino, currently CTO of RSoft, will be CTO for the combined entity. Financial terms were not disclosed. The merged company, to be named at a later date, will continue to develop its physical layer simulation solutions in Ossining, N.Y., under the RSoft brand, and its network products in Eatontown, N.J., under the NDTI brand.