Symmetries of WDVV equations

We say that a function F(τ) obeys WDVV equations, if for a given invertible symmetric matrix η^αβ and all , the expressions can be considered as structure constants of commutative associative algebra; the matrix η_αβ inverse to η^αβ determines an invariant scalar product on this algebra. A function x^α(z,τ) obeying is called a calibration of a solution of WDVV equations. We show that there exists an infinite-dimensional group acting on the space of calibrated solutions of WDVV equations (in different form such a group was constructed in A. Givental, math.AG/0305409]). We describe the action of Lie algebra of this group.