NEW YORK: Diversified industrial company  agreed to buy medical diagnostics company Beckman Coulter Inc for $83.50 per share. The deal represents an 11 percent premium to Beckman's closing price on Friday, and a roughly 45 percent premium over its price in December before rumors of a deal entered the marketplace, according to Beckman.  The transaction is valued at about $6.8 billion, including assumed debt, the companies said.