Hedge fund Elliott Management, which owns about 4% of Marathon Petroleum Corp. (NYSE: MRO), urged the refiner to conduct a strategic review and consider splitting into three businesses, separating its chain of gasoline and convenience stores or breaking into three businesses focused on retailing, refining and midstream operations that hold pipeline and storage assets, Elliott said on Nov. 21.

Marathon's shares were up 4% at $45.02 in early trading.

Elliott Management is an activist investor, and called Marathon Petroleum "severely undervalued," saying Marathon Petroleum could also look at transferring assets, which could go into an MLP, MPLX LP.

"Marathon's undervaluation is most glaring when the value of its three businesses is summed together," Quentin Koffey, a portfolio manager at Elliott, said in a letter to Marathon's board.

Elliott Management said its recommendations could help the company generate $14 billion to $19 billion for shareholders and boost the stock by more than 80%.

Marathon said in October it would transfer some assets into MPLX, which was created in 2012.

The move came after activist hedge fund Jana Partners, which raised its stake in Marathon Petroleum to about 0.8% during the week of Nov. 14, pushed the company to separate its pipeline and other midstream assets.

Jana's managing partner, Barry Rosenstein, said in October he supported the shift of assets to MPLX and the possible changes to Marathon's financial reporting that would result.

Up to the close on Nov. 18, Marathon Petroleum's shares had fallen about 16.5% in 2016.