Private equity firm Apollo Global Management LLC's first-quarter earnings rose fivefold from a year earlier as the value of its investments increased, in its first quarterly report since its March IPO.

Private equity firms have been benefiting from an improving economy and rising stock market valuations and have seen the value of their portfolios increase. They have also taken advantage of a rebound in M&A and stronger IPO markets to exit some of their investments.

Rival firms Blackstone Group and Kohlberg Kravis Roberts and Co both recently reported better first- quarter earnings that beat analysts' expectations.

Apollo, which was founded by former Drexel Burnham Lambert banker Leon Black in 1990, said first-quarter economic net income -- a measure private equity firms use to report -- was $390 million, up from $77 million a year earlier.

Adjusted ENI per share was about $1, according to Reuters calculations, which excludes compensation and tax. It was not immediately clear if this compares with the figure analysts estimated of 81 cents per share, according to Thomson Reuters I/B/E/S.

Apollo, which followed Blackstone and KKR in going public, said net proceeds of its IPO were $384 million.

Total assets under management were $70 billion as of the end of March, up from $56 billion the same time a year earlier.

Its shares are slightly lower than the $19 IPO price, closing on Wednesday down 23 cents at $18.48.

(Reporting by Megan Davies; Editing by Derek Caney and Maureen Bavdek)

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