DUBAI - Saudi Arabia's main sovereign wealth investment fund and Japan's Softbank Group plan to jointly study how robots can be used more effectively in government, business and society, they said on Wednesday.

In the coming months, the Public Investment Fund (PIF) and the Japanese technology firm will establish partnerships for the project with companies, academics and government bodies across the world, they said, without giving details.

The PIF, which is believed to have roughly $183 billion in assets, has been moving into a range of new industries as part of a drive to diversify the Saudi economy beyond oil.

Last year it invested $3.5 billion in U.S. ride-hailing firm Uber, and it plans to invest in a 334 square kilometre "entertainment city" south of Riyadh with sports and cultural facilities.

The robotics project is separate from the PIF's agreement last year to invest up to $45 billion over five years in the Softbank Vision Fund, a technology-focused private equity fund established with the Japanese company and other big investors.

(Reporting by Andrew Torchia; Editing by Elaine Hardcastle) ((andrew.torchia@thomsonreuters.com; +9715 6681 7277; Reuters Messaging: andrew.torchia.thomsonreuters.com@reuters.net))