The Blackstone Group L.P. (NYSE:BX) declared a troubled second quarter result as net earnings, defined by the firm as 'economic net income after taxes,' tumbled 74 percent to $212.3 million from $804.2 million last year, as reported in dealbook. Blackstone is the world's largest private equity firm. Earnings per share at $0.19 also missed street expectations of $0.21 a share. On a GAAP basis, Blackstone incurred a loss of $75 million, or 14 cents a share, against last year's profit of $86.2 million, or 18 cents a share.