A complex valued function f = u+ iv defined in a domain D ⊂ C, is harmonic in D, if u and v are real harmonic. Such functions can be represented as f(z) = h(z) + g(z), where h an g are analytic in D. In this paper we study some convolution properties preserved by the integral operator In H,λf, n ∈ N0 = N ∪ {0}, λ > 0, where the functions f are univalent harmonic and sense-preserving in the open...