Three events for the decay K+→π+νν̄ have been observed in the pion momentum region below the K+→π+π0 peak, 140<Pπ<199MeV/c, with an estimated background of 0.93±0.17(stat. )-0.24+0.32(syst.) events. Combining this observation with previously reported results yields a branching ratio of B(K+→π+νν̄)=(1.73-1.05+1. 15)×10-10 consistent with the standard model prediction.