The oil price slump is hitting Apollo Management really hard

On Thursday, Leon Black's Apollo Global Management reported a 72 percent drop in 2014's net income compared to the previous year.

Total net income after taxes fell from $2 billion in 2013 to $567.9 million. Income for the fourth quarter alone fell from $444 million in Q4 2013 to $93.8 million.

Apollo's assets under management also declined one percent to $159.8 million.

A source told the New York Times Dealbook that the steep fall in earnings resulted from trouble in the energy sector, most notably from falling oil prices. The NYT article pointed to one investment in particular, EP Energy, which saw a 40 percent decline in its share price in the fourth quarter.

Apollo's poor performance has also hit CEO Leon Black's personal paycheck. Bloomberg reported on Thursday that fellow private equity titan Steve Schwarzman has overtaken Leon Black this year as the richest man in private equity. While Apollo's earnings have fallen short, Schwarzman's Blackstone Group reported record profits in January.

"In 2014 Apollo continued to position itself for consistent long term growth, investment excellence and diversification," Black said in the earnings release statement. "We maintained our strong pace of realization activity, which resulted in total distributions for 2014 of more than $16 billion for our fund investors and $2.89 in cash distributions for our shareholders. In addition, the funds we manage deployed approximately $10 billion during the year across Apollo's integrated investment platform, which we believe can generate meaningful future returns for our investors and shareholders."