[en] In the E_6 inspired composite Higgs model (E_6CHM) the strongly interacting sector possesses an SU(6)×U(1)_B×U(1)_L global symmetry. Near scale f ≳ 10TeV the SU(6) symmetry is broken down to its SU(5) subgroup, that involves the standard model (SM) gauge group. This breakdown of SU(6) leads to a set of pseudo-Nambu-Goldstone bosons (pNGBs) including a SM–like Higgs and a SM singlet pseudoscalar A. Because of the interactions between A and exotic fermions, which ensures the approximate unification of the SM gauge couplings and anomaly cancellation in this model, the couplings of the pseudoscalar A to gauge bosons get induced. As a result, the SM singlet pNGB state A with mass around 750 GeV may give rise to sufficiently large cross section of pp → γγ that can be identified with the recently observed diphoton excess