General Motors Co. said that it will buy back $5 billion in shares by the end of 2016 and that activist investor Harry J. Wilson will give up his request for a board seat after reaching an agreement with the automaker, Bloomberg News reported yesterday. Wilson had requested a board seat and asked the Detroit-based company last month to use some of its cash to buy back $8 billion in shares. He was working with four hedge funds that collectively own more than 2 percent of the stock. GM also said that it will adopt a strategy to return free cash flow to shareholders while keeping investment grade credit and a minimum balance of $20 billion. The agreement with Wilson ends two months of discussions in which he urged Chief Executive Officer Mary Barra to return money to shareholders and be more open about company performance targets. As part of the announcement, GM also said that it’s investing in its business with a target of driving 20 percent returns on invested capital and will update shareholders on its progress every quarter.