BlackRock American Income Trust PLC is an externally managed investment trust that primarily invests in a diversified portfolio of North American equity securities, focusing on companies that pay and grow their dividends. The company delegates its investment management and administration to BlackRock Fund Managers Limited, which is responsible for the day-to-day operations and investment decisions. The investment strategy includes a stock-specific approach, with a portfolio typically comprising between 30 and 60 equity securities, and may also involve the use of derivatives and options for efficient portfolio management.