LONDON, June 21 (Reuters) - ** Feedgas flows into Cheniere Energy's Sabine Pass liquefied natural gas (LNG) export plant neared pre-outage levels on Thursday following an erratic supply profile this week, data showed. ** Input levels on the three pipelines serving the facility showed feed levels recovered to 2,888 million cubic feet/day (mcf/day) from 2,261 mcf/day on Wednesday. ** Current inflows suggest all four of the plant's liquefaction trains are in service following month-long maintenance on Train Three. (Reporting by Oleg Vukmanovic; Editing by Adrian Croft)