The Toyota-backed J-League club could lose a sizeable portion of its income after the Japanese government requested Chubu halt operations at its Hamaoka nuclear plant following last March's deadly earthquake and tsunami.
Neither Nagoya nor Chubu, who are staring at a loss of 110 billion yen since the disaster, were available for comment when contacted by Reuters.
However, Chubu's proposed pullout from their sponsorship deal with Grampus comes after the utility serving central Japan, including Nagoya, devised a plan to reduce costs by 130 billion yen by March, following the plant's suspension.
Japan's third-biggest power firm shut its sole nuclear power plant in Hamaoka, 120 miles southwest of Tokyo, last May.
Last year's 9.0 magntitude earthquake in north-east Japan and the giant tsunami which followed destroyed a power plant north of Tokyo, triggering a nuclear meltdown.
