The ldquoTransfermatrix-Methodrdquo [1, 2] has been adapted to evaluate also the free energy of triangular 2–d-Ising lattices. The present work considers a model with nearest-neighbour antiferromagnetic couplings and a fraction 1–x of spins removed at random sites leading to some frustration effects. It is not yet clear if such a system shows spinglass behaviour [3, 4]. The correlation function langs 0 s R rang2 (correlation between two spins with distanceR), which is related to the Edwards-Anderson-Orderparameter, shows such a fast breakdown with distanceR that there is a clear evidence against a phase transition at finiteT. In contrast to other models [1, 2, 5] we still expect an exponential decay of {langs 0 s R rang2} av with distanceR atT=0.