JPMorgan Chase & Co. agreed to quadruple its bid for Bear Stearns Cos. today in an attempt to overcome opposition from the firm’s shareholders, Bloomberg reported. Bear Stearns’ stock price almost doubled in response.

Bear Stearns shareholders will receive 0.21753 JPMorgan shares for each Bear Stearns share they hold, the firms said in a statement, valuing Bear Stearns shares at about $10 apiece. Under the terms of the deal the two firms made on March 16, the takeover price had been $2.52, based on last week’s closing price.

Bear Stearns surged almost 70 percent in early trading in New York after the New York Times reported the pending offer. Bear Stearns rose $3.98 to $9.94 at 8:30 a.m. before the shares were suspended from trading pending the announcement. The new terms value Bear Stearns at about $2 billion. JPMorgan CEO Jamie Dimon needs a majority of Bear Stearns shareholders to approve the deal and has been enticing the company’s employees with cash payments.

JPMorgan also struck a deal with the Bear Stearns board to purchase 39.5 percent of the company in a transaction that would not require shareholder approval, the companies said in the statement. Bear Stearns board members will vote in favor of the transaction, the companies said in the statement. To complete the deal, Dimon now needs approval from an additional 10 percent of shareholders. Employees owned about one-third of the outstanding shares before today’s dilution with the newly issued shares that the firm is selling to JPMorgan directly.