Large U.S. alternative investment managers continue to carry high levels of dry powder, according to a new report on the industry from ratings provider Fitch Ratings.  The elevated levels of uncalled investment capital come at a time when credit markets are competitive and valuations remain high. Dry powder for the firms in Fitch's review totaled $254.4 billion as of Sept. 30, 2015, representing a 35.2% increase from a year earlier, the company noted.  However, private equity firms are continuing to take advantage of market valuations by exiting investments for strong returns, Fitch observed. Income from exits has doubled for the...