Backs Principal Real Estate separate account, TPG Partners III and Ridgewood. : State of Michigan Investment Board has approved $144.4m (€126.1m) capital investment into real estate and infrastructure strategies, according to a board meeting document. The investment board, responsible for the investments of the $73.1b State of Michigan Retirement Systems, has approved a $44.4m committment into a Principal Real Estate Investors separate account, $50m into TPG Real Estate’s third opportunity fund and $50m into Ridgewood Infrastructure’s water and strategic infrastructure fund. The amount invested into Principal Separate Account will be used to develop a four-story 125,000sqft office building in Sunnyvale, California.