July 22 (Reuters) - Blackstone Group Inc, the world’s largest private equity firm, said on Thursday its second quarter distributable earnings nearly doubled year on year driven by a surge in asset sales across its real estate, private equity, credit and insurance businesses. Distributable earnings, which represents the cash used to pay dividends to shareholders, rose to $1.1 billion from $548 million a year earlier. This translated into a distributable earnings per share of 82 cents, surpassing the average Wall Street analyst estimate of 78 cents, data compiled by Refinitiv showed. Frenetic dealmaking by private equity firms such as Blackstone was a major driver in accelerating global mergers and acquisitions (M&A) activity in the second quarter, as companies were emboldened by vaccinations and low interest rates that supported economic recovery. Blackstone said its capital deployment reached a record $23.8 billion during the quarter. It also committed to investing an additional $28.5 billion in deals such as acquiring a majority stake in medical supplier Medline Industries Inc alongside Carlyle Group Inc and Hellman & Friedman. Buoyant capital markets and rising company valuations allowed Blackstone to cash out a lot of its investments. Total asset sales reached $19.6 billion, including the $2.9 billion divestment of its portfolio of warehouse and logistics assets in Australia. The buyout firm said its private equity portfolio grew 13.8% in the second quarter, compared with a 8.2% rise in the benchmark S&P 500 stock index over the same period. Opportunistic and core real estate funds rose 9.4% and 5.7%, respectively. Blackstone said its net income under generally accepted accounting principles doubled to $1.3 billion, driven by a sharp rise in investment income. Its total assets under management rose to $684 billion from $648.8 billion in the prior quarter. Unspent capital fell to $129.9 billion from $148.2 billion three months earlier owing to the pace of capital deployments. Blackstone declared a quarterly dividend of 70 cents per share. Reporting by Chibuike Oguh in New York; editing by Jason Neely Our Standards: The Thomson Reuters Trust Principles.