NATIONWIDE HAD 1986 PROPERTY-CASUALTY LOSS <Nationwide Mutual Insurance Co> said its property-casualty companies had a net loss of 56 mln dlrs last year while its life insurance operations earned 66.8 mln dlrs. Nationwide said its property-casualty group, the fourth-largest U.S. property-casualty insurer had a 106 mln dlr loss in 1986. Nationwide Life Insurance Co earned 62.8 mln dlrs in 1985, with last year's profit including record capital gains of 14.4 mln dlrs, up from gains of 2.6 mln dlrs the previous year. The company said its property-casualty group had a record loss from insurance operations last year of 859 mln dlrs after policyholders' dividends, up 25 pct from 1985's 710 mln dlrs. Nationwide said a surge in claims from personal auto insurance and the volatile commercial liability coverages during a period of unprecedented sales growth generated the loss. The company said over 576 mln dlrs of last year's group losses came from commercial insurance lines and 282 mln dlrs from its personal auto insurance business. Partially offsetting 1986's record insurance losses, Nationwide said, were record investment gains of 775 mln dlrs and a 28 mln dlr federal tax credit. The investment gains were up 39 pct from 1985's gains of 559 mln dlrs.