One of the biggest threats to big food brands in the U.S. lost steam in recent weeks.

The share of sales claimed by private-label products, or grocery items developed and sold by food retailers, has been decelerating in the latter half of 2018, analysts at Stifel led by Christopher Growe wrote in a note to clients Nov. 29, citing data from research firm IRI.

In the four weeks ended Oct. 21, own-branded products across all U.S. retailers gained 18 points of market share, a slower rate of expansion than earlier this year, when market share increased by nearly 140 basis points.

Many grocers have raised prices for their private brands in recent weeks — a move that is likely limiting their growth rate, according to the Stifel analysts. Private label brands at major U.S. retailers include Walmart Inc.'s Great Value and The Kroger Co.'s organic-focused Simple Truth.

The slowdown could be good news for manufacturers of branded food products, including The Kraft Heinz Co. and Conagra Brands Inc., which have had to contend with robust sales of private label products in recent years. Slower sales growth for branded products from those companies, such as Oscar Mayer hot dogs and Hunt's tomato ketchup, has led the manufacturers to revamp their current lineups as well as search for up-and-coming brands.

Private label products still pose a challenge to companies that rely on big brands, Growe said. Own brands have gained 73 basis points worth of market share so far in 2018, and the price gap between branded and private-label products has grown about 400 basis points over the past two years.

But data over the last four weeks "has slowly been improving and roughly half of the [food] companies in our coverage are now showing market share growth versus private label," Growe wrote.

Stifel confirmed its "buy" ratings on food companies including Conagra and Kraft Heinz, adding that they are "well-positioned in their categories or against private label in general."

Once viewed primarily as options for budget-conscious customers, private label products have been the object of investment by grocers in recent years. Kroger, privately held Albertsons Cos. Inc. and others have revamped their own-brand offerings to include more premium products as well as health-focused ones, such as organic items.

Private label has also been a key front as traditional grocers compete with Amazon.com Inc.'s Whole Foods Market Inc. Analysts have said Whole Foods' own-brand products provide Amazon an opportunity to expand its own private-label presence as it attempts to capture a larger portion of U.S. grocery sales.