Wall Street Journal – Federal prosecutors are investigating whether the top executive at Cantor Fitzgerald LP’s gambling unit participated in his company accepting illegal sports bets, according to people familiar with the matter. The potential alleged involvement of Lee Amaitis—a senior executive at the securities firm who founded Cantor Gaming nine years ago—came to light after a former executive at the unit, Michael Colbert, pleaded guilty to knowingly accepting illegal wagers. His plea was disclosed in federal court documents unsealed late last month. Cantor Fitzgerald, best known as a bond brokerage, operates sports books through its Cantor Gaming unit. The…