FRANKFURT, Dec 5 (Reuters) - German power groups Innogy and Uniper will join the MDAX index of mid-cap shares, having recently been spun off by utilities RWE and E.ON.
Stock exchange operator Deutsche Boerse said on Monday they would replace hospital operator Rhoen-Klinikum and machine tool maker DMG Mori AG, which will move to the SDAX index.
Shares in Innogy, which bundles RWE's healthy assets -- grids, retail and renewables -- have fallen around 14 percent since they started trading on Oct. 7.
Uniper, which E.ON split off to rid itself of ailing generation assets, has meanwhile gained about 15 percent since its listing in September.
The index changes take effect on Dec. 19. The next regular index review will be held on March 3. (Reporting by Maria Sheahan; editing by John Stonestreet)