LONDON, England (CNN) -- On March 30 the Open Skies treaty went into effect, liberalizing air travel between the U.S. and Europe. But how will the ease of restrictions on transatlantic routes affect business travelers? Under Open Skies, European and U.S. airlines will be given unlimited access between Europe and U.S. points. The treaty puts an end to the exclusive arrangement granted to British Airways, Virgin Atlantic, United Airlines and American Airlines to fly transatlantic out of London Heathrow. But with the airport currently operating at almost-maximum capacity, new flights will be severely limited. As a result competition is fierce for Heathrow slots, with airlines paying as much as $60 million to get their hands on them.
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Biggest challenge to Heathrow incumbents will come from SkyTeam alliance
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New flights start this year from Air France, Continental, Delta and Northwest
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BA will launch services between Continental Europe and New York in June
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