For an integral equation on the unit circle Gamma of the form (aI + bS + K)f = g, where a and b are Holder functions, S is a singular integration operator, and K is an integral operator with Holder kernel, we consider a method of solution based on the discretization of integral operators using the rectangle rule. This method is justified under the assumption that the equation is solvable in L-2(Gamma) and the coefficients a and b satisfy the strong ellipticity condition.