British Airways, American Airlines and Iberia may have to give up take-off and landing slots for their Oneworld transatlantic alliance to go ahead, the Financial Times reported. The airlines had planned to deepen the pact to take advantage of the US/EU “Open Skies” agreement, with the focus on routes between the United States, Mexico, Canada, the EU, Norway and Switzerland. But earlier the EU regulators said the plan may violate antitrust rules on restrictive business practices.