Northwestern Mutual Life Insurance said Wednesday it has approved a dividend payout of almost $5 billion for participating policyowners for 2012, the second largest payout in company history.

That's an increase of more than $125 million over its expected 2011 payout. About 90 percent of the dividend will go to permanent life insurance policyowners, while disability insurance policyowners will receive $252 million. Other categories receiving dividends are term life ($120 million), long-term care insurance ($12.8 million) and fixed and variable annuities ($27 million).

The company credits that payout to careful underwriting, rigorous expense management, diversified investing, and strong performance in other operating fundamentals.