  Closed bosonic string with different normal ordering constants $a \ne \bar a$
for the right and the left moving sectors is considered. One immediate
consequence of this choice is absence of tachyon in the physical state
spectrum. Selfconsistency of the resulting model in the "old covariant
quantization" (OCQ) framework is studyed. The model is manifestly Poincare
invariant, it has non trivial massless sector and is ghost free for $D=26, ~
a=1, ~\bar a=0$. A possibility to obtain the light-cone formulation for the
model is also discussed.
