Abstract. Formalism of the configuration-space Faddeev equations is applied to analyze the bound state problem of ΛNN system. The simulated NSC97f potential for ΛN interaction and semi-realistic NN potentials are used for calculations. We predict a broad Λnn resonance near threshold. A spin dependent three-body ΛNN potential has been proposed to explain experimental evidence for 3 Λ n bound state. The potential is defined by a Gaussian function of a hyper-radius. It was found that such potential with appropriate spin dependence does not support a bound state of 3 Λ n. A short range form of the potential generates non-physical solutions of the Faddeev equations.The HypHI Collaboration has recently reported evidence for a bound state of Λ + n + n system [1]. However, the bound 3 Λ n state has not been found under theoretical analysis (see for instance [2]). In the present work we construct a phenomenological three-body ΛNN potential with spin dependence that forms a bound state in the channel Λ + n + n (T =1, S =1/2). Such potential does not affect the ground state energy of 3 Λ H hypernucleus fixed by the experimental value of 0.13(5) MeV for the hyperon separation (or binding) energy Formalism of the configuration-space Faddeev equations was applied for Λ + n + n and Λ + n + p systems within an s-wave approach. The simulated NSC97f potential [3] for ΛN interaction and MT-I-III semi-realistic NN potential [4] were used for calculations. This model reproduces well the hyperon binding energy for 3 Λ H, with the value of 0.14 MeV (see also Ref.[5]). We have found a broad resonance in the channel Λ + n + n. The results of the calculations are presented in figure 1a). The method of analytical continuation in the coupling constant is used to calculate the parameters of the resonance [6]. The coupling constant is the coefficient γ which scales triplet component of the ΛN potential. The complex value of the Pade approximant calculated by set of negative energies (circles in figure 1a) for γ=1 gives the energy and width of resonance: E(γ = 1) = E r − i Γ 2 . Our result for the energy of the resonance is 0.2 MeV, that agrees with [7]. Within the presented model, the three-body ΛNN potential is treated as a perturbation of the Hamiltonian. It is defined as one range Gaussian: V 3b f (ρ) = −δ exp(−αρ 2 )S (s Λ , s NN ), where ρ is the hyper-radius: ρ 2 = x 2 + y 2 , with x, y the mass scaled Jacobi coordinates. The function S (s Λ , s NN ) depends on the spin variables of a hyperon (s Λ ) and NN pair (s NN ). Two free parameters δ and α have to be adjusted. We assume the ratio S (1/2, 1)/S (1/2, 0) to be equal 1 or 1/3 [2]. The calculations for α=0.1 fm −2 are shown in figure 1b). The three-body ΛNN potential resulted in a bound state of 3 Λ n generates Λnp over-bound states for S =1/2 and 3/2. The spin dependence, which provides a bound state of 3 Λ n and keeps the 3 Λ H ground state energy, cannot be considered as realistic. It was found that the short range form (when α>0.1 fm −2 ) of the potential generates non-physical ...