In a move which the SNP believes will put it on the side of "small government" in political debate, Alex Salmond, the party leader, will promise to slash the number of Executive departments from nine to six if he becomes first minister next May.
Mr Salmond has told Sir John Elvidge, head of the Scottish civil service, that he wants to create a government machine modelled on private sector companies which have small headquarters.
The SNP leader won agreement for the radical blueprint for devolved government from the party's shadow cabinet, which met last week to agree its approach to power.
Under the plan, which will be implemented as part of the "first 100 days" of an SNP-led Executive, the departments of development; education; enterprise, transport and lifelong learning; environment and rural affairs; finance and central services; health; justice; legal and parliamentary services and the office of the permanent secretary will be abolished.
They will be replaced by a department of the first minister and departments for finance and sustainable growth; health and well-being; education and skills; rural affairs; and justice.
A cabinet-level minister will be in charge of each of the six, reducing the number of senior ministers who are MSPs from 11 to six.
Mr Salmond has also decided that there will be a reduction in the total number of Executive ministers - including the Lord Advocate and the Solicitor General, who are not MSPs - from the current 20 to 18.
The cut in the number of cabinet ministers, who are paid 91,472 a year, and the reduction in overall numbers would reduce the salary bill for ministers, including their pay for being MSPs, from 1,923,971 to 1,546,119, a saving of more than a third of a million pounds a year.
The Scotsman understands that Mr Salmond accepts that reducing the number of departments to make the Executive "fit for purpose" will mean civil service job losses, though he has yet to put a figure to the number of posts that will go.
In a letter to Sir John - who will meet opposition party leaders in the run-up to the 2007 elections - Mr Salmond is understood to have drawn comparisons between the government and the private sector.
After studying the way that entrepreneurs such as Brian Souter, of Stagecoach and Sir Tom Farmer, who founded Kwik-Fit, run their companies, he has told Sir John that his model for government is to have small "headquarters functions" running Scotland.
In a separate private letter, Mr Salmond has also made a similar point to Sir John Ward, the chairman of Scottish Enterprise, questioning the need for the economic development quango to have 700 staff in its main office in Glasgow.
Mr Salmond last night refused to go into detail in advance of the publication of his party's plans, but he told The Scotsman: "Those who advocate public service reform, whether they be ministers or senior civil servants, should do so with credibility.
"To do that, they have to be prepared to reform themselves and to lead by example, from the top, not simply make appeals for reform to everyone else but themselves."
An Executive spokesman said: "The permanent secretary will respond in due course to the letter. It is normal practice for the permanent secretary to meet the leaders of the main opposition parties prior to an election - this happened in 1999 and again in 2003. In 2003, these meetings happened early in the new year, but timing is a matter for the permanent secretary to decide."