with: Brussels Airlines (SN2048, SN2050), Deutsche Lufthansa (LH5555, LH5609), ANA All Nippon Airways (NH5128), bmi regional (BM6048, BM6050), Etihad Airways (EY7230)
with: Singapore Airlines (SQ2149, SQ2145), Deutsche Lufthansa (LH959, LH955, LH953), United Airlines (UA9569, UA9562), ANA All Nippon Airways (NH5868)
with: British Airways (BA139, BA199), American Airlines (AA6659, AA6657), Jet Airways (India) (9W117), Iberia (IB7393), Air Canada (AC6002, AC6004)
with: British Airways (BA143, BA257), Air Canada (AC6008), Aeroméxico (AM7800), Jet Airways (India) (9W121), Air India (AI112), Avianca (AV2400), Virgin Atlantic Airways (VS300)
with: British Airways (BA836, BA826, BA834, BA838, BA824), S7 Airlines (S74709), American Airlines (AA6770), Japan Airlines (JL7825)
with: British Airways (BA912, BA902, BA916, BA904, BA910), Japan Airlines (JL7873, JL7821), American Airlines (AA6498)
with: British Airways (BA738, BA730, BA728, BA724, BA736), LATAM Chile (LA5571, LA5561), Japan Airlines (JL7707)
with: British Airways (BA676, BA680), American Airlines (AA6613, AA6465), Avianca (AV6616), Turkish Airlines (TK1984), Air Canada (AC6702), bmi regional (BM6361)
with: American Airlines (AA135, AA109), Finnair (AY5785, AY4014), British Airways (BA1502), Fiji Airways (FJ5068), El Al Israel Airlines (LY8071), Virgin Atlantic Airways (VS7)
with: Japan Airlines (JL7733, JL7793), Finnair (AY5984), British Airways (BA504, BA500), Cathay Pacific Airways (CX7203), Qatar Airways (QR5912), TAP Air Portugal (TP1357)
with: British Airways (BA960, BA956, BA948, BA952, BA954), Cathay Pacific Airways (CX7163), American Airlines (AA6386), Japan Airlines (JL7713)
with: SAS Scandinavian Airlines (SK810, SK804, SK806), South African Airways (SA7965), Etihad Airways (EY7473, EY7528), Singapore Airlines (SQ2662), Air Canada (AC9941)
with: Air Canada (AC849, AC859, AC857), Finnair (AY5999), British Airways (BA99), Iberia (IB7341), Ethiopian Airlines (ET1140), American Airlines (AA6213)
with: British Airways (BA716, BA718, BA710, BA712), LATAM Chile (LA5580), American Airlines (AA6565, AA6354), Japan Airlines (JL6533)
with: Deutsche Lufthansa (LH943, LH947, LH949), United Airlines (UA9549), Austrian Airlines (OS7366, OS7374), ANA All Nippon Airways (NH5866), South African Airways (SA7507)
with: Air Transat (TS565, TS265, TS293, TS209), Air Canada (AC1931), Deutsche Lufthansa (LH6716), Brussels Airlines (SN9629), United Airlines (UA8253)
with: Finnair (AY5479, AY5513, AY5515, AY5431), British Airways (BA2273, BA179, BA115), Jet Airways (India) (9W5812)
with: Eurowings (EW469, EW461, EW465, EW355), Air Canada (AC6948, AC6952), United Airlines (UA9646, UA9671)
with: British Airways (BA912, BA902, BA916, BA904, BA910), Japan Airlines (JL7873, JL7821), American Airlines (AA6498)
with: British Airways (BA716, BA718, BA710, BA712), LATAM Chile (LA5580), American Airlines (AA6565, AA6354), Japan Airlines (JL6533)
History
United Airlines has its roots in the Varney Air Lines air mail service of Walter Varney. In 1926 the airline flew the first schedule airline service in the country's history.
During the September 11, 2001 terrorist attacks, two of hijacked airplanes were United Airlines aircraft. An airline industry slump, coupled with economic hardship, increasing oil prices, and higher labor costs, led to the company losing $2.14 billion in 2001.
In 2011 United merged with Continental Airlines.