Berkshire Hathaway Inc.’s first-quarter earnings fell as turbulence across financial markets weighed on its giant stock portfolio and rising claims costs hurt its insurance-underwriting business.

Warren Buffett’s company reported net income of $5.46 billion, or $3,702 a Class A share equivalent. That was down from $11.71 billion, or $7,638 a share, a year earlier. Operating earnings, which exclude some investment results, edged up to $7.04 billion from $7.02 billion last year.