The 38-year-old 'Angels' hitmaker was slated to be one of the stars set to sing for the huge crowds at the top secret two-hour show to celebrate the end of the Olympic games in August, reported Mirror online.
He was planning to perform David Bowie's classic 'Life On Mars', but pulled out before rehearsals began last month to stay by his pregnant wife's side in Los Angeles.
"Robbie quit a few weeks ago. He had been lined up to perform solo material and it was hoped he would sing with Take That. However, just as rehearsals were kicking off, he said there was an unfortunate clash of dates," a source said.
A spokesman for Williams said, "He was asked to do the closing ceremony but due to the imminent birth of his baby, he couldn't take part."
