Updated from 11:28 a.m. EDTUpdate includes more details on first-quarter earnings as well as estimates of Berkshire's losses from natural catastrophes. OMAHA, Neb. ( TheStreet) -- Warren Buffett's Berkshire Hathaway ( BRK.A) Saturday reported preliminary first-quarter earnings of $1.51 billion, down from $3.63 billion in the same quarter last year. The decline in net earnings was partly attributable to Berkshire's insurance underwriting businesses, which lost $821 million during the quarter, vs. year-earlier earnings of $226 million. The company released the preliminary results at its annual meeting in Omaha. Also weighing on overall earnings was an $82 million loss on investments and derivatives. The company reported $1.41 billion in earnings in this category for the first quarter of 2010. > > Bull or Bear? Vote in Our Poll Earnings for Berkshire's railroad, utilities and energy businesses rose to $908 million from $505 million, while manufacturing, service and retail units earned $558 million, up from $477 million a year earlier. Ahead of Saturday's annual meeting, observers had wondered about Berkshire's insurance exposure to several recent natural disasters including the tsunami and earthquake that devastated Japan in March. In the news release announcing the preliminary first-quarter results, Berkshire broke out estimates for each event, saying it would likely incur losses of $1.07 billion from Japan's catastrophe, $412 million from New Zealand's Christchurch earthquake and $195 million from Australia's floods and Cyclone Yasi. Berkshire's Class A shares ended Friday down $55 at $124,750. The company's Class B stock finished the session up 3 cents at $83.30.