BERLIN (Reuters) - Germany's IG Metall union sees around a fifth of jobs at Thyssenkrupp at risk, a senior official was quoted as saying on Friday, following the conglomerate's recent plans to turn into a holding company.

On Monday, Thyssenkrupp said it would pursue plans to sell minority stakes in three of its five divisions, with the other two - submarines and steel - already in the process of being spun off or partly divested.

"The plans could see more than 20,000 employees' positions slashed," Juergen Kerner, deputy chairman of both the IG Metall union and Thyssenkrupp's supervisory board, told Sueddeutsche Zeitung (SZ) newspaper.

Thyssenkrupp has already announced plans to cut or outsource up to 11,000 jobs at its steel division TKSE and plans to slash around 1,800 jobs at its automotive unit.

Kerner said that Thyssenkrupp's supervisory board would meet in June to approve the spin-off of the group's submarine and warship division TKMS, which is planned for later this year.

Turning to steel, Kerner criticised Czech billionaire Daniel Kretinsky, who last year bought a 20% stake in TKSE and is in talks to acquire another 30% contingent on a job cuts deal with workers.

"I now consider Mr Kretinsky less and less to be the right buyer," Kerner said, adding the billionaire had resisted sharing his plans for the steel business for more than a year.

(Writing by Friederike Heine and Christoph Steitz; Editing by Matthias Williams and Susan Fenton)