(Reuters) - Britain's Heathrow Airport said on Friday it will remain closed through the day after a huge fire at a nearby electrical substation wiped out power, disrupting flight schedules of global airlines.

According to flight tracking website FlightRadar24, at least 120 inbound flights to Heathrow, Europe's busiest airport, were being diverted to other airports.

Here are the top 10 airlines by capacity that were set to arrive at Heathrow airport on Friday.

AIRLINE NAME FLIGHTS SEATS

British Airways 341 67,962

31 9,058

Virgin Atlantic

Lufthansa 21 3,780

American Airlines 20 5,744

Aer Lingus 19 3,484

17 3,673

United Airlines

SAS 14 2,520

Swiss 12 2,000

13 1,906

Eurowings

Delta Air Lines 11 2,687

Other 67 airlines 143 9,790

Total 669 145,836

Here is what airlines are saying about the closure:

* British Airways: "Due to a power outage in the LondonHeathrow area, London Heathrow Airport is currently closed. As aresult, customers due to travel from Heathrow on Friday areadvised not to travel to the airport until further notice. Thiswill clearly have a significant impact on our operation and ourcustomers and we're working as quickly as possible to updatethem on their travel options for the next 24 hours and beyond." * United Airlines: "Seven United flights returned to theirorigin or to other airports, and Friday flights to LondonHeathrow are being cancelled. We are working with our customersto offer alternative travel options." * Air India: "London Heathrow-bound AI129 from Mumbai isreturning to Mumbai; AI161 from Delhi is diverting to Frankfurt.All our remaining flights to and from London Heathrow, includingAI111 of this morning, have been cancelled for 21 March." * Aer Lingus: "Cancelling all flights to and from LondonHeathrow Airport until further notice today following theclosure of the airport by the authorities." * Virgin Atlantic: "This has had a significant impact on ourflying programme both into and out of Heathrow and all VirginAtlantic arriving and departing flights are cancelled untilmidday on 21 March, with the rest of today's schedule currentlyunder review." * Qantas: "Our Singapore-London and Perth-London serviceswere diverted to Paris today, with buses arranged to takecustomers on to London."Source: Data from Cirium Ascend, company statements.

Note: The seats represent capacity, not ticketed passengers.

(Reporting by Raechel Thankam Job in Bengaluru, Abhijith Ganapavaram in New Delhi and Jamie Freed in Sydney)