“…At our knowledge, the only subsequent treatment of this issue may be found in a paper by Gigante [16]. Recognizing the strict connection between the proportional reinsurance problem and the portfolio selection problem, early signalled by Pressacco [28], she applied the Karush-Kuhn-Tucker conditions ( [19], [20]) to the constrained quadratic optimization problem arising from the mean-variance approach to proportional reinsurance.…”