(KTRS) – Monsanto says that $62 billion, just is not enough from Bayer to buy the biotech giant.

The board of directors rejected the German company’s bid. Monsanto’s Chairman and CEO, Hugh Grant, says the proposal “significantly undervalues” the company. Monsanto officials say they are open to negotiations.

Bayer can now raise its bid, walk away, or try to begin a hostile takeover.