Adds detail on potential successors in paragraphs 4-5

By Melanie Burton and Clara Denina

MELBOURNE/LONDON, May 22 (Reuters) - Rio Tinto RIO.AX 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.

Rio said in a stock exchange filing that a selection process is underway. Contenders for the top job are expected to include current Chief Commercial Officer Bold Baatar, head of iron ore Simon Trott and aluminium boss Jerome Pecresse.

Investors said they expected Rio to mount a robust external search given limited bench strength internally. But Rio's board may have to compete for external candidates with BHP BHP.AX, whose CEO Mike Henry is widely expected to step down this year.

Several people said the announcement had caught 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," analyst Glyn Lawcock at Barrenjoey in Sydney.

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.

"You've got to give him credit for restoring some relationships with stakeholders," said portfolio manager Andy Forster of Argo Investments in Sydney.

Rio Tinto doubled down on its lithium bet this week, announcing that it will partner with Chile's Codelco for its Maricunga lithium project with a $900 million investment.

"They've made all the decisions around lithium and now they just have to execute," Forster said, adding the "jury was still out" on the long term lithium outlook.

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.

(Reporting by Rishav Chatterjee in Bengaluru and Melanie Burton in Melbourne and Clara Denina in London; Editing by Savio D'Souza and Jan Harvey)

((Rishav.Chatterjee@thomsonreuters.com;))