On 17 October 2007, the creation of a profit and revenue-sharing transatlantic joint venture between Air France-KLM and Delta Air Lines was announced during a press conference at Air France-KLM's headquarters. The venture became effective on 29 March 2008. It aimed to exploit transatlantic opportunities to capture a major share of long-haul business traffic from London Heathrow Airport, which opened to unrestricted competition on that day as a result of the "Open Skies" pact between the EU and US. It was envisaged that Air France and Delta would begin nine daily round trips between London-Heathrow and destinations in the USA, including a daily London (Heathrow) to Los Angeles service by Air France. Once the new Air France-Delta venture received antitrust immunity, it was to be extended to the other two transatlantic SkyTeam partners, enabling all four partners to codeshare flights as well as to share revenue and profit. The new transatlantic joint venture marks the Air France-KLM Group's second major expansion in the London market, following the launch of CityJet-operated short-haul services from London City Airport that have been aimed at business travellers in the City's financial services industry. However, the daily London (Heathrow) to Los Angeles service was not as successful as hoped, and was discontinued in November 2008.