Pick one category for the following text. The options are - company, educational institution, artist, athlete, office holder, mean of transportation, building, natural place, village, animal, plant, album, film or written work. United Energy Systems of Ukraine - United Energy Systems of Ukraine (UESU) (Ukrainian: ) was a natural gas trading company in Ukraine. In the years 1995 and 1996 it was the largest natural gas importer in Ukraine. The company was affected by a series of financial irregularities leading to criminal charges against the principals and closure of the company in 2009.
The answer to this question is:
Company