New sufficient conditions are derived for the integral operator of mereomorphic functions defined by $$ H(z)=\frac{c}{z^{c+1}}nt_{0}^{z}u^{c-1}(uf_{1}(u))^{\gamma_{1}}\dotsm(uf_{n}(u))^{\gamma _{n}}\,du, $$ to be in the class $\Sigma_{N}(\lambda)$ of meromorphic functions satisfying the condition $-\Re\{\frac{zf^{rime rime}(z)}{f^{rime}(z)}+1\}