Katie Schmuecker, associate director of IPPR North, said the region needed a powerful advocate, especially if Scotland gained independence or more powers.
She spoke out ahead of the publication of a new report today on the impact on the north of England of such changes.
The study, Borderland, said an independent or fiscally autonomous Scotland would struggle to make deep cuts in corporation tax, but could gain an advantage by using a combination of air passenger duty and economic development grants.
It said the north of England should be involved in talks taking place in pro-UK parties over extra powers for Holyrood if Scots reject independence. Ms Schmuecker said: "The north of England needs a Salmond figure to win 'devo-more' from London.
"Scotland's First Minister helps the Scottish economy speak with one voice and is able to win concessions from London.
"The North needs a powerful advocate to demand far more powers and resources from London in order to give us more control over our economic destiny, and to begin to level the playing field with Scotland.
"Otherwise, the north risks falling further behind Scotland, whether or not Scots vote for independence."
Mr Salmond is due to address the North East Economic Forum annual dinner in Newcastle tonight.
The report says the Scots economy would have to grow by 3.9% to offset the cost of a 20% cut in corporation tax, the reduction pledged by SNP ministers.
It says cutting the main business tax to 12.5% – the Irish model backed by some Scots business figures – would require a 7.8% rise in gross domestic product to maintain public spending.
The report says such growth would be a "tall order" and Scotland's ability to sharply cut taxes would be constrained.
A Scottish Government spokeswoman said: "We welcome this report and its finding that an independent Scotland with responsibility for its own taxes will be well-placed to 'outshine competition' from elsewhere."
However, Scottish Labour's Ken Macintosh MSP, said: "This report shows the SNP's economic policy is financially illiterate."