The 51-year-old has signed a short-term contract until the end of the season, with the aim of keeping the club in the top flight in the campaign's remaining five matches.
'A wealth of experience'
"We have every confidence in Michael Frontzeck steering the club to safety. In the games that remain, our goal is that Hannover 96 remain in the Bundesliga - nothing else matters," commented Reds' club president Martin Kind.
Sporting director Dirk Dufner added: "From Tuesday evening, Michael can immediately begin to prepare the team for Saturday's important game against Hoffenheim. He knows the Bundesliga and boasts a wealth of experience. I'm convinced he can end the season successfully with the team."
Return to Lower Saxony
Frontzeck's last post was at current Bundesliga 2 side FC St. Pauli, which he left in November 2013. He previous experience of coaching in Germany's top tier includes stints at Borussia Mönchengladbach (2009-11), DSC Arminia Bielefeld (2008-09) and Alemannia Aachen (2006-07), while he was also assistant coach at Hannover during the 2004/05 campaign.
Korkut was relieved of his duties after Matchday 29's 4-0 loss at Bayer 04 Leverkusen extended Hannover's winless run to 13 games and left them just two points above the relegation play-off spot.