It could be the summer before the Westminster Government responds on proposals to cut corporation tax, Peter Robinson has said.
The Scottish administration also wants the power to set its own levy and has used Northern Ireland's discussions to help stake its claim, the DUP leader added.
A ministerial working group from London and Belfast is examining the region's case for a reduction to promote inward investment.
The First Minister said: "I suspect that on the present timetable we are more likely to be talking about a response from the Government in the summer than any time before that."
He said Scottish independence was not discussed at last week's British/Irish Council meeting in Dublin.
"It is a matter entirely for the people of Scotland as to what they should determine their future to be but I very much hope that it will be as an integral part of the UK," he told the Assembly.
"There is an irony that at the moment, when there seems a real possibility of some form of break-up of the UK, that Northern Ireland is not the cause of it."
In December ministers from Stormont and Westminster said they had constructive discussions over plans to cut corporation tax in Northern Ireland. The meeting was the first time they had met to discuss dropping the rate of corporation tax in NI from 26% to match the 12.5% in the Irish Republic.
If agreed, the tax cut would have to be accompanied by a proportionate reduction in the block grant - the money Northern Ireland gets from the Treasury. That could be a cut of more than £400 million a year.
In October, Finance Minister Sammy Wilson said that if agreed, it would be at least four years before the corporation tax level in Northern Ireland is cut.