Salmond made his comments despite widespread anger over Finance Secretary Derek Mackay’s handling of rates revaluation, which comes into effect in April.
Many small businesses are objecting to the changes, claiming they could go out of business as a result of crippling increases in the levy.
Salmond said that rates revaluations were always controversial, whatever the circumstances, but acknowledged that there were some cases of “genuine concern”.
He said: “Of course there’s an argument against some of the rates rises and of course people are feeling the hard edge of it.
“In the north-east there’s a very legitimate case because the date the independent evaluation officers made their valuations was at a time when, a couple of years ago, the economy was much stronger than now.
“That’s why I welcome Aberdeenshire Council’s initiative to put £3 million into additional rates relief to try and take some of the edge off for the hardest cases.”
The revaluation is being carried out by independent assessors. Mackay has been urged to review the process.
Yesterday Conservative shadow finance secretary Murdo Fraser said: “Alex Salmond says there is a legitimate case for action.
“ If Derek Mackay won’t listen to thousands of affected firms, perhaps he will listen to his former boss.”
Mackay’s spokesman said: “Even by Tory standards this is a pretty pathetic distortion of what Alex Salmond actually said.
“We agree there are some firms in the north-east who face a challenge – which is exactly why we have worked with local authorities on schemes that could support those businesses.”