The two companies are scheduled to meet next week and tour the 255,600 barrel-per-day refinery, which has been idled since late August, a day before Hurricane Ida roared over the area and swamped the site.
Phillips 66 spokesperson Bernardo Fallas declined to comment.
Marathon spokesperson Jamal Kheiry said the company does not comment on “rumor or market speculation.”
It was unclear if Marathon was interested in acquiring the refinery or operating it through a joint venture with Phillips 66, one of the people said.
Phillips 66 said in November it would convert the Alliance refinery into an oil and refined products terminal to take advantage of its location on the Mississippi River, 20 miles (26 km) south of New Orleans.
Hurricane Ida caused flooding that breached the flood wall around the refinery and inundated control systems causing millions of dollars of damage to the facility.
At least three companies were potential buyers of the refinery before the hurricane struck. They included Hilcorp, Valero Energy (VLO.N) and Saudi Aramco’s Motiva Enterprises (MOTIV.UL), people familiar with the matter had said