This paper is concerned with the following problem: given two rational functions

and

, otherwise arbitrary but for which

has no zeros in the right-half plane,

is to be realized as the driving-point impedance of a lossless coupling two-port terminated in the impedance

. This problem had been previously considered and solved by Schoeffler and by Wohlers when

and

are positive real functions and the coupling network is reciprocal. Necessary and sufficient conditions are given here for realizability in the contemplated form when neither of the two impedances are necessarily positive real and when the coupling network may be reciprocal or nonreciprocal, but still lossless. A realization procedure is described and examples are given to illustrate the approach.