A measure of the combined earnings of the Bloomberg Dry Bulk Shipping Pureplay Index will retreat 51 percent this year, according to analysts’ estimates compiled by Bloomberg. STX Pan Ocean Co., the biggest member of the gauge, will report a loss of $33.8 million, compared with net income of $94.95 million in 2010, according to the mean of seven estimates. Shares of the Seoul-based company fell 35 percent this year.