Blackstone Group LP said Thursday its first-quarter profit tumbled as its selling of older investments waned during another period of market volatility. The New York private-equity firm reported earnings of $150 million, or 23 cents a share, down from $629.4 million, or $1 a share, a year earlier. Blackstone's first-quarter economic net income fell to $371 million, or 31 cents a share, from $1.62 billion, or $1.37 a share, a year earlier.
