Nissan is prepared to reject an acquisition offer that would make it a subsidiary of Honda, according to a person familiar with the matter, a move that could jeopardize talks between the two carmakers to join forces.

The Yokohama-based company plans to convene a board meeting as soon as Wednesday afternoon, where it will likely vote down Honda’s proposal to buy Nissan’s shares and make it a subsidiary, said the person. The Japanese automakers have been in discussions for weeks on a combination that would effectively result in an acquisition of Nissan, as Honda’s ¥7.3 trillion ($47 billion) valuation is nearly five times higher.

The board’s final decision could still be in flux as some senior officials at Nissan support the Honda offer, the person said.