Prudential Financial on Tuesday reported a 21.5% rise in second-quarter adjusted profit as the insurer's U.S. unit benefited from a higher net investment spread and more favorable underwriting.

Its U.S. businesses reported adjusted operating income of $956 million for the second quarter, compared with $573 million a year ago.

Investment returns at major insurers have rebounded this year as easing concerns around an economic downturn and high interest rates drive a rally across major Wall Street indexes.

In comparison, the previous year was marked by heavy losses in capital markets amid uncertainty triggered by the war in Ukraine, decades-high inflation and fears of an imminent recession.

Prudential's assets under management were roughly flat at $1.4 trillion in the second quarter.

"We continue to execute on our strategy to reduce market sensitivity and invest in businesses that support our long-term growth," said CEO Charles Lowrey in a statement.

Prudential has been looking to shift its business focus from market-sensitive revenue segments to more stable and recurring sources of income such as underwriting.

The company's after-tax adjusted operating income came in at $1.09 billion, or $2.94 per common share, for the three months ended June 30, compared with $895 million, or $2.34 per common share, a year earlier.

Prudential said it returned $713 million to shareholders in the second quarter, including $250 million of share repurchases and $463 million of dividends.

(Reporting by Manya Saini in Bengaluru; Editing by Devika Syamnath)