By Chibuike Oguh NEW YORK, Feb 9 (Reuters) - Apollo Global Management Inc APO.N said on Thursday its fourth-quarter adjusted net income rose 77% owing to strong earnings from its retirement services business, although that was partly offset by a steep decline in its private equity portfolio. The growth in Apollo's earnings was largely the result of the $685.2 million income it generated from investing the capital of retirement services provider Athene Holdings. Like its peers, Apollo cashed out fewer investments during the quarter amid financial market volatility, inflation, recession worries and geopolitical tensions.