An institutional investor has re-entered the market as a buyer of Mortgage Choice shares, despite threats that the company faces legal action from stressed franchisees.The share price of the embattled mortgage broking company recovered slightly last week after Sydney-based fund manager Pinnacle Investment Management increased its exposure to the business.Pinnacle last week acquired more than 2.5 million shares in the company to boost its stake to 7.24 per cent from 5.2 per cent.Pinnacle was particularly active on 27 June when it acquired 1.34 million shares worth $1.77 million.The fund manager's heavy buying spree accounted for 77 per cent of all on-market purchases of Mortgage Choice stock that day.However, the biggest seller of the stock last week was one of Mortgage Choice's most loyal long term investors - the Bermuda-based investment group FIS Limited.FIS, which hasn't engaged in any trading of the stock in almost two years, offloaded 1.3 million shares on 27 June. It now owns 13.7 million shares in the company, which accounts for 11 per cent of the issued scrip.Mortgage Choice's share price plunged by 30 per cent last month following Fairfax Media reports that franchisees were considering mounting a civil action against the company.The share price closed up six cents or 4.2 per cent to $1.47 on Monday.