Emirates airline said on Thursday it had rejected demands by London’s Heathrow Airport to cut capacity despite being threatened with legal action, and said it intended to continue operating its six daily flights to Britain’s busiest airport. Heathrow this week asked airlines to stop selling tickets for summer flights, limiting the number of daily passengers flying from the hub to 100,000 to ease pressure on operations that have been unable to keep up with demand. Emirates, owned by the government of Dubai, said Heathrow had given the airline 36 hours from Wednesday to reduce capacity on its si…