The stock was down 11.55% to $25.73 a share.
Conagra reported adjusted earnings of 67 cents a share in the period vs. analysts' expectations of 56 cents. GAAP EPS was 31 cents. Revenue was $2.38 billion, which missed Wall Street's estimates of $2.41 billion.
The per-share earnings were 22% higher than last year's second quarter. Net sales increased 9.7%, in part because of the acquisition of Pinnacle Foods for $10.9 billion in cash and stock.
"In the short time since completing the Pinnacle acquisition, our team has been working hard on a seamless integration and an intense diagnostic to clarify both the challenges and opportunities within the Pinnacle portfolio," said President and CEO Sean Connolly. He added, "While we have identified challenges, they are clearly executional, not structural, in nature. We are aggressively applying Conagra's proven brand-building and innovation playbook to restore share growth."
Conagra guided for full year 2019 EPS of between $2.03 and $2.08. Net sales for the year are expected to grow 22% to 23%.
Conagra, with a market cap of $14 billion, has declined 31.71% this year.