INSURANCE

Lincoln National to Buy Delaware Management: The company said it signed a definitive agreement to acquire closely held Delaware Management Holdings Inc. for about $510 million, including the assumption of $209 million of debt. The transaction also provides for a contingency payment of $22.5 million based on future revenue growth. The shareholder selling the largest stake of Philadelphia-based Delaware Management Holdings, an investment adviser firm, is an investment partnership managed by New York merchant bank Castle Harlan Inc. Ft. Wayne, Ind.-based Lincoln National Corp. is the holding company for a group of insurance and financial services businesses.