MELBOURNE (Reuters) - Rio Tinto CEO Jakob Stausholm will step down later this year once a successor is appointed, the world's largest iron ore miner said on Thursday, adding that a selection process for the role is underway.

The company named Stausholm as its top boss in 2020 while grappling with legal, public and investor angst over the destruction of the 46,000-year-old Juukan Gorge rock shelters.

Stausholm took over as CEO from Jean-Sebastien Jacques who was ousted as a result of Rio Tinto's handling of the saga.

He will continue at the helm of the firm till a new chief is appointed.

Analyst Glyn Lawcock at Barrenjoey in Sydney said the announcement had taken the market by surprise, since Stausholm was only five years into a tenure that typically extends to six.

"He's done a good job on the soft issues," Lawcock said.

Those included repairing relationships after Juukan Gorge, advancing Rio Tinto's Oyu Tolgoi copper project in Mongolia, and getting its relationship with China's Chinalco back on track after it was strained by tensions over their joint Simandou project, he said.

Contenders for the top job are generally expected to include current Chief Commercial Officer Bold Baatar and head of iron ore Simon Trott.

"A rigorous selection process is already underway, led by the Nominations Committee," Rio said in a statement on the London Stock Exchange.

Danish businessman Stausholm has formerly served as Rio's finance chief and a member of the board of advisors at IBM, and held senior positions at shipping company A.P. Moller - Maersk.