Shares of the Findlay, Ohio, company dropped 0.8% to $56.71 at last check.
Marathon Petroleum reported a GAAP net loss of $242 million, or 37 cents a share compared to a net loss of $9.2 billion, or $14.25 a share, in the year-ago period. The oil refiner posted an adjusted net loss of $132 million, or 20 cents a share.
Revenue rose 9% to $22.88 billion from $20.99 billion in the same period a year ago.
A survey of analysts by FactSet produced consensus estimates of a GAAP loss of 71 cents a share, or an adjusted loss of 72 cents a share, on revenue of $19.35 billion.
"During the first quarter, our industry continued to struggle with effects of the pandemic," said Michael J. Hennigan, Marathon's president and chief executive officer, in a statement.
"With the COVID-19 vaccination roll-out, we are beginning to see increases in global mobility and demand for transportation fuels. For the first time since the pandemic began our Refining and Marketing business generated positive adjusted EBITDA," he added.
In addition, Hennigan said that Marathon Petroleum will continue to reposition itself with the pending sale of Speedway and its investments in renewables projects.
For the second quarter, FactSet's survey is calling for GAAP earnings of 21 cents a share, or adjusted earnings of 48 cents, on revenue of $20.74 billion.