The rumour comes from the French site MacBidouille and is quoted by CNET.
Financial analysts are already assessing the implications.
FBR Capital Markets say that if ARM gets a third of Apple's computer slots it would cost Intel $740 million in lost revenue in 2017 and add $7 million to ARM's revenue.
However if Apple switches to ARM for all its computers then it would cost Intel $2.59 billion a year in lost revenues and add $34 million to ARM's revenue.
And if ARM moves further out into the PC market and takes 18% of it then Intel would lose $6 billion a year in revenue and ARM would gain $72 million a year.