The deal is worth $63.50 per share

The deal is worth $63.50 per share Shares of Baldor Electric Co. leaped 40 percent before the market opened Tuesday after Swiss industrial manufacture robot maker ABB Ltd. offered to buy the electrical motor maker for $3.1 billion.

The deal is worth $63.50 per share, a 41 percent premium to Baldor's closing stock price on Monday.In premarket trading, Baldor shares rose $18.20, or 40.4 percent, to $63.31.Including debt, the transaction would be worth $4.2 billion. Baldor is based in Fort Smith, Ark.

ABB said it wants to expand in North America, which is already its biggest market. It also said it's the right time to make a deal, as demand ramps up for energy efficient products.The U.S. market for high-efficiency motors is expected manufacture to grow 10 to15 percent next year on the back of new regulations, effective in December. Similar regulations in Canada, Mexico and Europe are expected next year as well.