* Merkel loses second minister to academic cheating * Embarrassment but little election impact seen * Schavan says will sue university over Ph.D decision (Removes extraneous 'and' in 8th paragraph) By Annika Breidthardt BERLIN, Feb 9 (Reuters) - Germany's education minister resigned on Saturday after being stripped of her doctorate for plagiarism, embarrassing Chancellor Angela Merkel and depriving her of a close ally in the run-up to a September election.

BERLIN, Feb 9 (Reuters) - Germany's education minister will resign on Saturday after being stripped of her doctorate over plagiarism charges, sources from the ruling coalition said, an embarrassment for Chancellor Angela Merkel as she campaigns to win a third term in office. Merkel and her close ally Annette Schavan were due to hold a joint news conference at 1300 GMT and the sources said they would announce the resignation then.

Germany's education minister and a close ally of Chancellor Angela Merkel was fighting for her political life Wednesday after being stripped of her doctorate for plagiarism seven months ahead of elections. Annette Schavan vowed to launch a legal battle against Duesseldorf University's ruling on her thesis, "Person and Conscience", written 33 years ago, amid opposition calls for her to resign. "I will not accept the decision by the University of Duesseldorf and will file a lawsuit against it," she said in a brief statement in South Africa where she is on a five-day visit.