The Committee of Scottish Bankers reported that at 3091, the number of business start-ups recorded during the third quarter of 2012 was 16.1% behind the previous quarter.
It was also 12.2% down on the same period last year.
The figures are based on information from the four CSCB member banks – Bank of Scotland, Clydesdale Bank, Lloyds TSB Scotland and Royal Bank of Scotland.
The findings contrast with Scottish Government figures published last month that showed the number of small employers and self-employed individuals rose by close to 10% between 2011 and 2012
A spokesman for the Federation of Small Businesses in Scotland said: "It is entirely possible that the most recent wave of gloomy economic indicators have dissuaded a proportion of would-be entrepreneurs from taking the plunge.
"However, other statistics such as those collected by the Scottish Government, the Hunter Centre for Entrepreneurship and the Business Gateway service all paint slightly different pictures with most pointing to a rise in self-employment and a small increase in the smallest employers.
"Therefore, these statistics may show that a larger proportion of start-ups are choosing a bank alternative to those that collect these statistics."
Setting up a business has become more expensive after Google decided to stop offering its web-based office software, including Gmail, for free to small businesses.
The local authority with the largest number of business start-ups was Glasgow City at 334, a reversal of the same period last year when Edinburgh was ahead.
However, this figure was still down on the 346 new businesses recorded by the banks in the same period last year and the 468 founded in the city in the second quarter.
Some of the change in the overall totals could be down to the established banks ceding market share.
A recent Scottish Government survey found that Lloyds Banking Group, owner of Bank of Scotland and Lloyds TSB Scotland, and Royal Bank of Scotland account for 70% of the small and medium-sized enterprise banking market, down from 77% two years ago.
Meanwhile, Clydesdale Bank has pulled out of the property sector.