Craig Anderson, senior business partner at KPMG in Scotland, said:
It is clear that the business community is still seeking to have concerns allayed as we move closer to September 18.
Our research suggests that most businesses probably do not feel sufficiently informed to make appropriate long-term plans, with any action likely to be taken only when the outcome is known.
More top news
The Tory party's "anti-immigration rhetoric" could cost MPs key marginal seats in the forthcoming general election, a new report says.
Two pilots have broken the world distance record for a flight in a helium balloon after soaring over the Pacific Ocean.
The number of terminal cancer patients who die in hospital rather than at home is placing "unnecessary strain" on the NHS, a report says.