BERLIN—Germany has sworn in a new education minister after her predecessor stepped down over claims that she plagiarized parts of her doctoral thesis decades ago.

In a low-key ceremony Thursday, President Joachim Gauck formally accepted the resignation of Annette Schavan, who denies the plagiarism allegations and has vowed to contest her university's decision to strip her of her doctorate.

He swore in Johanna Wanka, a mathematician, former university professor and outgoing regional education minister in the state of Lower Saxony. That state's conservative-led government narrowly lost a regional election to the center-left opposition last month.

Both Schavan and Wanka are members of Chancellor Angela Merkel's Christian Democratic Union party.

Duesseldorf's Heinrich Heine University revoked Schavan's doctorate this month after concluding that she plagiarized parts of her 1980 thesis.