A study of B+c→K+K−π+ decays is performed for the first time using data corresponding to an integrated luminosity of 3.0  fb−1 collected by the LHCb experiment in pp collisions at center-of-mass energies of 7 and 8 TeV. Evidence for the decay B+c→χc0(→K+K−)π+ is reported with a significance of 4.0 standard deviations, giving σ(B+c)σ(B+)×B(B+c→χc0π+)=(9.8+3.4−3.0(stat)±0.8(syst))×10−6. Here B denotes a branching fraction while σ(B+c) and σ(B+) are the production cross sections for B+c and B+ mesons. An indication of ¯bc weak annihilation is found for the region m(K−π+)<1.834  GeV/c2, with a significance of 2.4 standard deviations.