  In the presence of penguin contributions, the indirect CP asymmetry in B^0(t)
--> pi^+ pi^- measures sin 2alpha_{eff}, where alpha_{eff} deviates from the
true value of the CKM phase alpha by an amount theta, i.e. alpha_{eff} = alpha
+ theta. Using the measured value of direct CP asymmetry in B^0(t) --> pi^+
pi^-, we derive new bound on |2 theta|.
