with: Brussels Airlines (SN2048, SN2050), Deutsche Lufthansa (LH5555, LH5609), ANA All Nippon Airways (NH5128), bmi regional (BM6048, BM6050), Etihad Airways (EY7230)
with: British Airways (BA2105, BA2103, BA2111, BA2107), Aer Lingus Irish Airlines (EI273, EI263, EI277), United Airlines (UA7663)
with: Singapore Airlines (SQ2149, SQ2145), Deutsche Lufthansa (LH959, LH955, LH953), United Airlines (UA9569, UA9562), ANA All Nippon Airways (NH5868)
with: Brussels Airlines (SN2064, SN2066), Deutsche Lufthansa (LH5625, LH5627), ANA All Nippon Airways (NH5138), bmi regional (BM6064, BM6066), Hainan Airlines (HU8570)
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 (AA6753, AA6445), British Airways (BA51, BA57, BA55), Virgin Atlantic Airways (VS461), Air Canada (AC6852), Finnair (AY5945)
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 (AC6198, AC6186, AC6200), Austrian Airlines (OS452, OS458), United Airlines (UA9846), Japan Airlines (JL7729), British Airways (BA706)
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: Brussels Airlines (SN2174, SN2184, SN2178), ANA All Nippon Airways (NH5162), Air Canada (AC6373), bmi regional (BM6178), Aegean Airlines (A33011), Hainan Airlines (HU8557)
with: Aer Lingus Irish Airlines (EI211, EI203, EI205), British Airways (BA2081, BA2073, BA6165), Etihad Airways (EY5162, EY7975)
with: Deutsche Lufthansa (LH943, LH947, LH949), United Airlines (UA9549), Austrian Airlines (OS7366, OS7374), ANA All Nippon Airways (NH5866), South African Airways (SA7507)
with: British Airways (BA1423, BA1419, BA1417), Qatar Airways (QR5994, QR5992), Qantas Airways (QF3548), Japan Airlines (JL7126), American Airlines (AA6396)
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.