NEW YORK (AP) - A fight is brewing between the NFL and insurers over who will pay to defend the league against former players' lawsuits over head injuries.

Some Travelers Companies Inc. subsidiaries filed a lawsuit Tuesday in New York. They say they insured the league's merchandising arm, NFL Properties, and shouldn't have to pay for a joint defense including the league itself. Another insurer, Alterra America Insurance Co., sued the NFL last week.

Meanwhile, the league sued Travelers and other insurers last week in Los Angeles. The NFL says it wants "to ensure an orderly and comprehensive determination" of insurers' obligations.

Lawsuits involving more than 2,400 retired players accuse the NFL of failing to act on evidence showing repeated hits to the head can cause long-term health problems. The NFL denies the allegations.