Legg Mason Inc., the Baltimore-based asset manager, reported on Wednesday that assets under management in August were $711.2 billion, up 8.5 percent from $644.5 billion in August 2013. Fixed income investments closed at $367.9 billion, an increase from last year’s $347 billion. Managed assets in stocks this August totaled $197.9 billion versus $163.5 billion in the same month last year. Liquid assets, such as money-market mutual funds, rose to $145.4 billion, up from the $134 billion reported in August 2013. Month over month, AUM was up from $693.3 billion in June.