  The two-loop four-point amplitude of two massless SU(N) colored scalars and
two color singlet operators with different virtuality described by a half-BPS
and Konishi operators is calculated analytically in maximally supersymmetric
Yang-Mills theory. We verify the ultraviolet behaviour of the unprotected
composite operator and exponentiation of the infrared divergences with correct
universal values of the anomalous dimensions in the modified dimensional
reduction scheme. The amplitude is found to contain lower transcendental weight
terms in addition to the highest ones and the latter has no similarity with
similar amplitudes in QCD.
