HANOI, Nov 15 (Reuters) - A court in Vietnam on Monday sentenced an aquaculture farmer to seven years in prison after finding him guilty of spreading "anti-state propaganda" on Facebook (FB.O) , state media reported. Nguyen Tri Gioan, 42, was convicted of "making, storing, spreading information, materials, items for the purpose of opposing the state" at a one-day trial in the central province of Khanh Hoa, the official Vietnam News Agency said.Despite sweeping economic reform and increasing openness to social change, Vietnam"s ruling Communist Party retains tight media censorship and tolerates little criticism. Gioan was accused of posting poems and images on his Facebook accounts to "distort, slander and defame the leadership of the (Vietnam Communist) party, the state and leader Ho Chi Minh," the report cited the indictment as saying. Reuters could not immediately reach his lawyer for comment. There was no immediate response from Facebook. The report said Gioan pleaded guilty at the trial. Once the jail term is over, he will be placed under house arrest for three years, it said.