(Adds segment earnings details, adds poultry plant acquisitions, updates share price, adds byline)
By Karl Plume
Feb 7 (Reuters) - Tyson Foods Inc reported weaker-than-expected first-quarter sales on Thursday as the largest U.S. meat processor was stung by weaker pork prices and sales volumes and lower chicken prices.
Shares of the maker of Ball Park hotdogs and Jimmy Dean sausages fell about 2 percent to $59.66.
Tyson is grappling with a drop in U.S. demand for chicken and declining prices for pork due to trade tensions between the United States and some trading partners.
Top pork importers Mexico and China have both raised tariffs on U.S. pork shipments in retaliation for higher U.S. duties on their goods, leading to a glut of meat in the United States.
Tyson has been focusing on expanding further into value-added foods like chicken nuggets, while also growing its footprint outside of the United States.
CEO Noel White said in a statement that Tyson's pork and chicken units "performed well given market conditions," and highlighted the company's recent M&A growth.
"We remain focused on stabilizing volatility and growing earnings in Prepared Foods as well as our value-added and international businesses. We are facing several challenges this year. We do every year," White said during a conference call with analysts.
Tyson's first-quarter revenue fell 0.4 percent to $10.19 billion in the fiscal first quarter ended Dec. 29, below expectations for $10.38 billion, according to IBES data from Refinitiv.
Sales in the company's pork business fell 8.1 percent, as prices fell on average 4.6 percent compared to last year, while average chicken prices fell more than 13 percent, Tyson said.
The company reaffirmed its earnings-per-share guidance for fiscal 2019 of $5.75 to $6.10, but said adjusted operating margins in chicken would narrow to 6 percent in 2019, from 8 percent the prior year, as U.S. chicken production is forecast to rise.
Beef margins were expected to increase from the company's earlier outlook, while pork margins were expected to hold steady.
Tyson on Thursday announced it reached an agreement to buy four poultry plants in Thailand and two in Europe from Brazilian food company BRF S.A.. That followed its acquisition of Keystone Foods, a leading supplier of chicken nuggets to fast-food chain McDonald's Corp in late July.
Net income attributable to the company fell to $551 million, or $1.50 per share, from $1.63 billion, or $4.40 per share, a year earlier, when it received a one-time tax benefit. Analysts had expected earnings of $1.56 per share, according to Refinitiv IBES data.
Excluding items, Tyson earned $1.58 per share. (Reporting by Karl Plume in Chicago, additional reporting by Jaslein Mahil in Bengaluru; Editing by Shinjini Ganguli and Alistair Bell)