This paper deals with the stability analysis of implicit Runge-Kutta methods for the numerical solutions of the systems of neutral delay differential equations. We focus on the behavior of such methods with respect to the linear test equations

y'(t)	=	L*y(t) + M*y(t-) + N*y'(t-), t 0
y(t)	=	g(t), - t 0

where > 0, L, M and N are d x d complex matrices. We show that an implicit Runge-Kutta method is NGP-stable if and only if it is A-stable.

MINISIMPOSIUM SESSION: 3. Numerical methods for delay equations (2 sessions)