UK's Heathrow airport says planned third runway may be delayed until 2039

(Corrects date in second bullet point to 2035 from 2029)

Sept 26 (Reuters) - Britain's Heathrow Airport said on Saturday the opening of its planned third runway could be delayed until 2039. 

Here are a few details: 

• "Our focus has always been to secure planning permission by 2029. Once achieved the runway will be open within a decade," a spokesperson for Heathrow said in an emailed statement.

• The UK's biggest airport said that 2035 had been an "ambitious target" which would have needed significant changes in regulations and policy.

• Opening a new runway within a decade of receiving the planning permission has always been the "core scenario" for Heathrow.

• Britain's Labour government last year backed a third runway at Heathrow, one of the world's busiest airports, arguing that the project would support economic growth.

• The government approved Heathrow's £49 billion ($64.92 billion) expansion and upgrade plan, which included £15 billion of upgrade work already planned and the cost of building the runway, re-routing London's orbital motorway and adding a new terminal, put at about £33 billion.

• Located west of London, Heathrow is Europe's busiest airport and operates at full capacity. Its two runways compare with four each in Paris' Charles de Gaulle and Frankfurt Airport, and six at Amsterdam's Schiphol.

($1 = 0.7548 pounds)

(Reporting by Chandni Shah in BengaluruEditing by Gareth Jones)