FRANKFURT, Nov 23 (Reuters) - German carbon specialist SGL Carbon SGCG.DE will re-enter Germany's mid-cap MDAX index .MDAXI , replacing GSW Immobilien GIBG.DE , which is dropping out after being taken over by peer Deutsche Wohnen DWNG.DE . "Due to the takeover by Deutsche Wohnen, the free float of GSW has dropped below 10 percent, making it ineligible for inclusion in the index," Frankfurt stock exchange operator Deutsche Boerse DB1Gn.DE said in a statement late on Friday. SGL Carbon was just relegated from the MDAX to small-caps index SDAX .SDAXI on Sept. 5. Deutsche Boerse said Villeroy & Boch VIBG_p.DE , a maker of tableware and bathroom ceramics, would now replace SGL Carbon on the SDAX. The changes will become effective on Nov. 27, Deutsche Boerse said. (Reporting by Maria Sheahan; Editing by Bob Burgdorfer) ((maria.sheahan@thomsonreuters.com)(+49 69 7565 1286)(Reuters Messaging: maria.sheahan.thomsonreuters.com@reuters.net)) Keywords: GERMANY INDEX/