NEW YORK (Reuters) -BlackRock's assets hit a record high $11.6 trillion in the fourth quarter of last year as the world's largest money manager posted a 21% profit jump, with fee income buoyed by stronger equity markets.

Assets managed by the New York-based company increased to $11.55 trillion from $10.01 trillion a year earlier and $11.48 trillion in the third quarter.

Net income rose to $1.67 billion, or $10.63 per share, in the three months to Dec. 31 from $1.38 billion, or $9.15 per share, a year earlier.

Client assets were buoyed by a U.S. stock market rally after Donald Trump's presidential election victory in November, with investors betting on lower corporate taxes and deregulation.

BlackRock's quarterly results complete a banner year for the asset manager, which has sought to strengthen its position in rapidly growing private markets, spending about $25 billion last year on infrastructure investment fund Global Infrastructure Partners and private credit business HPS Investment Partners.

"For many companies, periods of M&A contribute to a pause in client engagement. At BlackRock, clients are instead embracing and rewarding our strategy," CEO Larry Fink said in a statement on Wednesday.

BlackRock registered $201 billion in long-term net inflows in the fourth quarter. Total net inflows hit $281.4 billion, up from $95.6 billion a year ago.

A majority of the long-term inflows were captured by exchange-traded funds (ETFs), at $142.6 billion. Clients poured in $23.8 billion into BlackRock's fixed-income products.

Assets under management mainly depend on two factors - the performance of investments, and money flowing in and out of the funds. The benchmark S&P 500 index gained 2.1% in the fourth quarter and finished the banner year up 23.3%, marking its second straight year of gains exceeding 20%. Elsewhere, the MSCI's gauge of stocks across the globe fell 1.2% in the fourth quarter but finished up 15.7% in 2024, marking its second straight yearly gain.