The Scotsman is facing a downturn in advertising and circulation
Managers at The Scotsman and Scotland on Sunday have announced they are to merge their editorial departments, prompting further job losses.
They are understood to be looking for 25 redundancies as the group faces a sharp downturn in advertising revenue and in circulation.
It has been reported The Scotsman is facing its first annual loss in 192 years of publishing.
Similar changes are being implemented at The Herald and Sunday Herald.
Arts and culture sections within the weekend editions of The Scotsman and Scotland on Sunday are being closed.
There will be a merger of the reporting teams covering news, features, sport, politics and business.
A spokesman for the National Union of Journalists said newspaper proprietors could not keep cutting jobs at this sort of rate and expect readers to keep faith with the quality of the product.
Under the new plans, John McLellan has been confirmed as editor-in-chief and editor of The Scotsman and Ian Stewart as editor of Scotland on Sunday.
Tom Little will move from Scotland on Sunday to become editor of the Edinburgh Evening News.
Michael Johnston, Johnston Press Scottish division managing director, said: "The objective behind these changes and proposals is to ensure our publications are produced as efficiently as possible in the face of very challenging economic and trading conditions.
"Through careful implementation of the proposals described - and through the skill and professionalism of our editorial staff - the company is sure that the quality, individual style and integrity of our publications will be preserved and improved".
Johnston Press, which owns The Scotsman and hundreds of local newspapers throughout Britain, announced on Friday it was selling its headquarters in Edinburgh's Manor Place, and will move management into The Scotsman office at Holyrood.
Meanwhile, a union meeting at the Daily Record/Sunday Mail earlier heard their dispute was moving to a conclusion, with promises from management over the way redundancies are handled in future, and changes to work patterns.
Journalists have been on strike for seven days over the past four weeks, in protest at 23 planned compulsory redundancies. That number has been reduced, while more than 35 journalists from the total of 240 are taking voluntary severance payments.