Andover (Mass.) Contributory Retirement System officials want to move $22 million into core-plus fixed income. The $96 million fund wants to move into a more enhanced strategy, said Rosemary Guillette, senior associate for consultant Segal Advisors. The assets are currently in a core bond portfolio run by Hartford Investment Management, which can rebid. officials hope to have a selection by July 31. Elena Kothman, the systems board administrator, referred questions to Segal Advisors.