* Move comes after debate over use of jet, cronyism
* Anders Nyren proposed as new Industrivarden chairman
* Handelsbanken CEO to become chairman of bank
* New Handelsbanken CEO to be unveiled before AGM
STOCKHOLM, Jan 22 (Reuters) - Swedish investment group Industrivarden said on Thursday its chairman, Sverker Martin-Lof, would leave his positions at the group and its companies this spring, leading to a string of management changes at big Swedish firms.
The move comes after reports by Swedish daily Svenska Dagbladet into the liberal use of a corporate jet by senior staff and a media debate over how control of boards within the group has been held by a small number of executives.
Industrivarden said in a statement its owners had taken note of the recent debate and would make changes.
"The intention is therefore that the following principles shall apply in the future: Senior executives of portfolio companies shall not serve on Industrivarden's board," it said.
Industrivarden said Anders Nyrén, currently chairman of banking group Handelsbanken, would take over as the new chairman of Industrivarden from Martin-Lof, one of the most powerful figures in Swedish business.
Industrivarden also said Handelsbanken's Chief Executive Par Boman would be proposed as new chairman of the bank, new chairman of SCA and as a new director of construction group Skanska.
"An announcement on a successor to Par Boman as CEO of Handelsbanken will be made by its board of directors prior to the bank's Annual General Meeting," the group said.
It added that Bengt Kjell would take over as chairman of steel maker SSAB from Martin-Lof.
Industrivarden has large holdings in a number of top Swedish firms including truck maker Volvo, telecom gear maker Ericsson, engineering firm Sandvik, Handelsbanken, and Skanska. (Reporting by Helena Soderpalm; Editing by Mark Potter)