NEW YORK • When Roseanne Barr's head was on the chopping block, she begged the head of Disney-ABC Television Group for mercy.

On Thursday, she revealed in a tweet that she had appealed to Mr Ben Sherwood for a reprieve after a storm broke over her comparison of former White House adviser Valerie Jarrett to an ape.

"I begged Ben Sherwood... 2 let me apologise & make amends.

"I begged them not to cancel the show. I told them I was willing to do anything & asked 4 help in making things right. I'd worked doing publicity4 them 4free for weeks, travelling, thru bronchitis," she wrote.

She also "begged4 ppls jobs" given that hundreds of people depended on the sitcom for a living.

But Barr, 65, said Mr Sherwood bluntly told her that what she had done was unforgivable, USA Today reported.

The show, which was ABC's most-watched programme in the previous TV season, was cancelled even as Barr apologised to Ms Jarrett.

On Thursday, Barr also offered an olive branch to two cast members - Michael Fishman and Sara Gilbert - whose distancing from her racist jibes had initially upset her.

"I forgive u both, love u both, just wish u could have called me personally 2 talk rather than do it in a public arena.

"I understand, tho. It's ok," Barr tweeted.