Elon Musk has knocked Twitter shares after warning he would undertake serious staffing cuts. 

Mr Musk told prospective investors in his buyout of Twitter that he would run the company with a skeleton crew, according to The Washington Post. 

Twitter shares closed the day almost 5 per cent down on their opening price. 

Investment analyst Dan Ives says Twitter is due for some job cuts, but the reported figure went too far.

“Musk cannot cut his way to growth with Twitter and a number in the 75 per cent zip code would be way too aggressive in our opinion out of the gates,” he wrote.

Mr Musk and Twitter have been given until October 28 by a Delaware judge to work out details of the proposed US$44 billion buyout. 

If no deal is reached, there will be a trial in November.