* Both Games bid chiefs to stay on and lead preparations (Updates with bid chiefs to stay on as heads of Games)
LIMA, Sept 13 (Reuters) - Paris was awarded the 2024 summer Olympics and Los Angeles the 2028 Games on Wednesday, as the International Olympic Committee (IOC) broke with decades of tradition to vote on a unique double allocation.
Paris, which has hosted two previous Olympics, will stage the event 100 years after its last Games in 1924 while Los Angeles will also organise its third Games after 1932 and 1984.
IOC President Thomas Bach embraced both cities' mayors on stage after a unanimous show of hands by IOC members ratified the awards.
The announcement was celebrated in Paris with the unveiling of a giant set of interlaced rings, the symbol of the Games, in a heavy downpour on the Trocadero square with lights glittering on the Eiffel Tower in the background.
"In the coming seven years we will prepare the Olympic Games with all our energy," French President Emmanuel Macron, who had personally campaigned for the bid, said.
"Together we must do everything in our power to ensure that Paris hosts a magnificent games in 2024."
The IOC decided in July to award both Games at the same time, following the withdrawal of four of the six cities bidding for the 2024 Olympics, amid concerns about the size, cost and complexity of organising the world's biggest multi-sports event....