The indirect RKKY interaction in a layered metal with nearly nested (almost squared) Fermi surface is evaluated analytically. The final expressions are obtained in closed form as a combination of Bessel functions. We show that the expected "2k_F" oscillations occur as the far asymptote of our expressions, where the value of the effective Fermi momentum k_F depends on the direction in r-space. We demonstrate the existence of the intermediate asymptote of the interaction which is of the sign-reversal antiferromagnetic type. This part of RKKY interaction is the only term surviving in the limit of exact nesting. A good agreement of our analytical formulas with numerical findings is found until the interatomic distances.