(Bloomberg) -- Blackstone Group LP, the largest manager of alternative assets such as private equity and real estate, doubled first-quarter earnings as assets swelled past $300 billion for the first time.

Economic net income, a measure of earnings excluding some costs, rose to a record $1.62 billion, or $1.37 a share, from $813.9 million, or 70 cents, a year earlier, the New York-based firm said today in a statement. Analysts had estimated the firm would earn $1.03 a share, according to the average of 14 estimates in a Bloomberg survey.

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