Dutch telecommunications company Royal KPN NV said Monday it has agreed to buy the outstanding shares of iBasis Inc., a Massachusetts-based wholesale international long distance carrier, for $3 each in cash.

The tender offer represents a 131 percent premium over the closing price of $1.30 on July 10, the day before the offer was announced. IBasis shares shot up 72 cents, or 32 percent, to $2.98 on Monday after the deal was announced.

The offer for the 44 percent of shares in iBasis that KPN does already not own expires at midnight Dec. 8. The price values the remaining minority stake at about $93.3 million.

The deal settles a lawsuit by iBasis against KPN, which called a previous offer for $1.55 per share "grossly inadequate."

Ibasis also agreed to terminate its July 30 stockholder rights plan.

The special committee of iBasis recommended that stockholders accept KPN's last and final offer.

If 90 percent of the outstanding shares are tendered, the remaining stockholders will also be bought out. Of the 31.1 million shares outstanding, just 491,707 had been tendered as of Friday night.