British Airways (BA) is the largest airline in the United Kingdom based on fleet size, or the second largest, behind easyJet, when measured by passengers carried.
 The airline is based in Waterside near its main hub at London Heathrow Airport.
 In January 2011 BA merged with Iberia, creating the International Airlines Group (IAG), a holding company registered in Madrid, Spain.
 IAG is the world's third-largest airline group in terms of annual revenue and the second-largest in Europe.
 It is listed on the London Stock Exchange and in the FTSE 100 Index.
The history of Scandinavian Airlines System (SAS) from 1933 to 1951 covers the first attempts at transatlantic travel, the establishment of a consortium and finally the establishment of the consolidated SAS.
 Aerotransport, the national airline of Sweden, and Det Norske Luftfartselskap (DNL), the national airline of Norway, both started planning transatlantic routes in the mid-1930s.
 By 1939, negotiations were started with Det Danske Luftfartselskab (DDL) of Denmark, and by 1940 services were to begin.
 Because of the German occupation of Denmark and Norway, the plans collapsed.
 In Sweden, Svensk Interkontinental Lufttrafik (SILA) was founded to start private transatlantic flights, which commenced in 1945.
 Negotiations were started again, and in 1946 the consortium Overseas Scandinavian Airlines System (OSAS) was established to start routes to New York and South America.
Air Caraïbes is a French airline and is the regional airline of the French Caribbean which comprises two overseas departments of France: Guadeloupe and Martinique.
 The airline is headquartered in Les Abymes in Guadeloupe.
 and its main base is Pointe-à-Pitre International Airport, with a hub at Le Lamentin Airport, near Fort-de-France.
 It operates scheduled and charter services serving 13 islands in the West Indies.
 It also operates transatlantic flights to Paris using Airbus A330 and Airbus A350 aircraft under the Air Caraïbes Atlantique brand.
 The airline code shares with LIAT.
Gol Linhas Aéreas Inteligentes S.A ("Gol Intelligent Airlines S.A." also known as VRG Linhas Aéreas S/A) BM&F Bovespa: GOLL3, GOLL4 / is a Brazilian airline based in São Paulo, Brazil.
 According to the National Civil Aviation Agency of Brazil (ANAC), between January and December 2015 Gol had 35.9% of the domestic and 13.6% of the international market shares in terms of passengers per kilometer flown, making it the largest low-cost airline in South America and the second largest Brazilian airline company by market share and fleet size, after LATAM Brasil.
 Gol competes in Brazil and other South American countries with Chilean LATAM Airlines Group, Brazilian Azul and Colombia-based Avianca Holdings S.A.
 It also owns the brand Varig, although now that name refers to what is informally known as the "new" Varig, founded in 2006, not to the extinct "old" Varig airline, founded in 1927.
Zoom Airlines Ltd was a British scheduled, low-fare, transatlantic airline, the sister company to Zoom Airlines Inc. based in Canada.
 Zoom Airlines Ltd was based in Crawley, West Sussex, England.
TransAtlantic Lines LLC is an American shipping company based in Greenwich, Connecticut.
 The limited liability company was founded in 1998 by vice-president Gudmundur Kjaernested and president Brandon C. Rose.
 The company owns and operates 5 vessels, including one tug-and-barge combination.
 Four of these vessels are chartered by the Military Sealift Command, and perform duties such as delivering cargo to U.S. military activities in Diego Garcia.
 TransAtlantic maintains resident agents in the U.S. District of New York and other federal Districts to receive service of process.
 TransAtlantic Lines has no collective bargaining agreements with seagoing unions.
Zoom Airlines Inc. was a Canadian low-fare scheduled transatlantic airline with its headquarters in the Place Bell Canada building in Ottawa, Ontario.
 Zoom operated year-round scheduled services to Europe, and charter services to South America, Caribbean, and Southern United States destinations with Canadian tour operators.
OpenSkies is a transatlantic airline owned by British Airways (BA) that is headquartered in Rungis near Paris.
 The airline launched as a brand of BA European Limited in June 2008 but in April 2009 the name was transferred to Elysair (which had operated as L'Avion).
 The airline is a full-service carrier and offers three class service cabins on board its aircraft.
 The airline currently operates between Paris-Orly Airport in France and both Newark and New York in the United States.
Caledonian Airways was a wholly private, independent Scottish charter airline formed in April 1961.
 It began with a single 104-seat Douglas DC-7C leased from Sabena.
 Caledonian grew rapidly over the coming years to become the leading transatlantic "affinity group" charter operator by the end of the decade.
 During that period, passenger numbers grew from just 8,000 in 1961 to 800,000 in 1970.
 The latter represented 22.7% of all British non-scheduled passengers.
 It also became Britain's most consistently profitable and financially most secure independent airline of its era, never failing to make a profit in all its ten years of existence.
 By the end of 1970, Caledonian operated an all-jet fleet consisting of eleven aircraft and provided employment for over 1,000 workers.
 At that time, its principal activities included group charters between North America, Europe and the Far East using Boeing 707s, and general charter and inclusive tour (IT) activities in Europe utilising One-Elevens.
 This was also the time Caledonian merged with British United Airways (BUA), the largest contemporary independent airline and leading private sector scheduled carrier in the United Kingdom, and formed British Caledonian.
LATI (Linee Aeree Transcontinentali Italiane, "Italian Transcontinental Airlines") was an early transatlantic airline operating between Italy and South America between 1939 and 1941.
 Although the transatlantic service was permanently discontinued in December 1941 following the entry of the United States into World War II, the company continued to exist until 1956.

Question: which airline is based in Waterside and owns OpenSkies transatlantic airline?
Answer: the largest airline in the United Kingdom based on fleet size