(Reuters) - Conagra Brands ( CAG ) missed Wall Street expectations for third-quarter sales on Thursday, as supply-chain disruptions in frozen food and refrigerated business hurt its ability to meet demand.

Shares of the Slim Jim and Duncan Hines cake mixes maker fell 3.5% in premarket trading, amid broader market declines.

Conagra is facing a double whammy of slowing sales growth as budget-conscious Americans switch to cheaper private-label brands, and manufacturing disruptions at one of its primary facility, which prepares and cooks chicken used in frozen meals, hurting supply.

"While shipments lagged consumption largely due to the discrete supply constraints we announced in February, we are making solid progress in restoring inventory and improving customer service levels," CEO Sean Connolly said.

The packaged food company's net sales fell to $2.84 billion during the quarter, from $3.03 billion a year earlier. Analysts on an average estimated $2.90 billion, according to data compiled by LSEG.