Chat show host The Scot had hoped to succeed
But the role of host went to rival
The Springburn-born stand-up comic and actor told his audience, parodying
Ferguson has hosted the The Late Late Show for nine years - both programmes are produced by Letterman's production company, Worldwide Pants.
The actor, who created the character
"I feel doing this show for 10 years, that's enough."
He added that he had previously threatened to quit, but was persuaded to stay. "About two years ago, I had decided after eight years... that it was probably time for me to move on.
Since becoming the host of The Late Late Show in 2005, Ferguson has achieved the highest ratings since the programme started in 1995
The comedian mixed humour with serious issues, paying a moving on- screen tribute to his father after his death and also won praise for his interview with South African Nobel Peace Prize winner Desmond Tutu.
A former electrical apprentice Ferguson, who moved to
Raised in a council house in Cumbernauld, he now owns a pound(s)2m stately home in
But the star will not be unemployed long, he is already lined up to host Celebrity Name Game, a game show starting this autumn and is developing TV projects through his own production company.
Chat show host
The Scot had hoped to succeed