A new integrable two-component system with cubic nonlinearityFollowing the considerable progress in nanoribbon technology, we propose to model the nonlinear Frenkel-like excitations on a triangular-lattice ribbon by the integrable nonlinear ladder system with the background-controlled intersite resonant coupling. The system of interest arises as a proper reduction of first general semidiscrete integrable system from an infinite hierarchy. The most significant local conservation laws related to the first general integrable system are found explicitly in the framework of generalized recursive approach. The obtained general local densities are equally applicable to any general semidiscrete integrable system from the respective infinite hierarchy. Using the recovered second densities, the Hamiltonian formulation of integrable nonlinear ladder system with background-controlled intersite resonant coupling is presented. In doing so, the relevant Poisson structure turns out to be essentially nontrivial. The Darboux transformation scheme as applied to the first general semidiscrete system is developed and the key role of Bäcklund transformation in justification of its self-consistency is pointed out. The spectral properties of Darboux matrix allow to restore the whole Darboux matrix thus ensuring generation one more soliton as compared with a priori known seed solution of integrable nonlinear system. The power of Darboux-dressing method is explicitly demonstrated in generating the multicomponent one-soliton solution to the integrable nonlinear ladder system with background-controlled intersite resonant coupling. C 2015 AIP Publishing LLC.[http://dx.doi.org/10.1063/1.4914510] under the proper choice of spectral L(n|z) and evolution A(n|z) operators. Here, the integer n standing for the discrete spatial coordinate runs from minus to plus infinity, the letter z marks the time-independent complex-valued spectral parameter, while the overdot assumes the differentiation over the time variable τ:ḟ (n) ≡ d f (n)/dτ. In its original formulation, 1 the system of our interest has been derived relying upon certain Laurent-type form of 4 × 4 square matrices L(n|z) and A(n|z). In doing so, the analysis of a limiting spectral problem dictated by the auxiliary spectral operator a) vakhnenko@bitp.kiev.ua