University of Massachusetts President Robert Caret during his installation ceremony four years ago. 

After just four years on the job, the president of the University of Massachusetts is leaving his post. Robert Caret is resigning to become the chancellor of the University of Maryland System.

Earlier this year, Caret signed a three-year extension to his contract with the UMass Board of Trustees, so his move comes as a big surprise to both state lawmakers and the university’s public relations team.

Meanwhile on Twitter, the president of University of Maryland congratulated Caret, saying ‘Welcome home to Maryland.’

Caret previously served as president of Towson University, which is part of the University of Maryland system.

Henry Thomas, chairman of the UMass Board of Trustees, told The Associated Press that he was disappointed to learn of Caret's decision but said a "first-class search" would begin for a successor.

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UMass Lowell chancellor Marty Meehan has been considered an early favorite to succeed Caret. Three years ago, Meehan was passed over in a search for a new president. But Meehan tells WGBH he has not been contacted by the university about the soon-to-be open position.