Metamaterial slabs of hexagonal arrays of metallic triangular nanoprisms are studied. Constitutive parameters are calculated using standard retrieval method. Bi-layered structures show both electric and magnetic resonances, due to the symmetric and anti-symmetric hybridized plasmonic states. Hybridized modes frequencies can be tuned by shifting one layer relative to the other one. Negative index of refraction in the optical range is obtained as a result of hybridized states inversion.