LAGOS, May 15 (Reuters) - Nigerian oil output has been reduced by 170,000 barrels per day (bpd) since last Thursday when villagers occupied a major oil pipeline hub feeding the Bonny export terminal, Shell <RDSa.L> said on Tuesday. The output comprises 137,000 bpd of Shell-operated volumes and 33,000 bpd from other companies, a company spokesman said.