Alan Peterson has joined Aetna Inc. in Hartford, Conn. as a portfolio manager overseeing the firm's roughly $500 million in high-yield assets, according to people with knowledge of the situation. He replaces Jean LaTorre, who was promoted to head of fixed-income after Tim Corbett left for Hartford Insurance Co. earlier this year. Peterson's last position was as high-yield portfolio manager for CIGNA, which has since spun off and renamed its asset management arm as TimesSquare Capital Management. However, he left that firm close to a year ago. Peterson did not return calls, and LaTorre declined comment.