Sands and Clark will leave at the end of the year. In addition to the commercial changes, GN&M managing editor Chris Elliott will step down from the board in June 2010, when key projects he is currently running on behalf of the board are completed.
Sands said that given "changing shape and needs of the business" it is "the right time" to leave.
In other changes, Adam Freeman, currently commercial director of GN&M, is promoted to director, consumer media. In the new role, he takes responsibility for display ad sales, newspaper sales, marketing and for the financial performance of the Guardian, Observer and guardian.co.uk.
Colin Hughes joins the GN&M board in the new role of Director of Business and Professional. He retains his current responsibility for Guardian Professional, the company's business-to-business division, and takes on responsibility for Guardian Jobs.
Also, Jon Cornaby, who was appointed Finance Director in January, is promoted to the GN&M board. Derek Gannon becomes director of operations, taking on responsibility for printing and distribution, while retaining the remit for technology, HR and other support functions.
Stella Beaumont takes up a new role, director, international and Business Development, focusing on the company's growth outside the UK.
Marc Sands, marketing director and Joe Clark, director and general manager, Newspapers are leaving the company.
The company said the changes will allow for swifter decision-making and "better cross platform working".
Tim Brooks, managing director of GN&M, said the new structure is "designed to meet the longer-term needs of the business".
In July, Guardian Media Group posted a pre-tax loss of £89.8m for the year to 29 March, division GN&M reporting a pre-tax loss of £36.8m.
This article was first published on mediaweek.co.uk