Aetna Life & Casualty's net income fell 11.7% to $920.6 million for fiscal 1987. The results include extraordinary tax benefits of $50 million from utilization of prior net operating losses and $4 million of capital gains, the Hartford, Conn., company said. The company said that in its employee benefits division, insurance profits declined due to escalating health claim costs and losses from the development of alternative health-care operations. The company posted higher earnings in its personal financial security and commercial insurance divisions. Revenue was up 7.8% to $22.1 billion.