Dec 19 (Reuters) - Lamb Weston LW.N kept its annual sales forecast intact for the second time this year on Friday even as the frozen potato supplier handily beat quarterly results estimates, signaling muted demand for the rest of the fiscal year.

Shares of the company, which also supplies potato sides and appetizers to fast-food chains such as McDonald's MCD.N and Yum Brands YUM.N, were down nearly 18% in early trading.

The reaffirmed forecast despite the quarterly numbers implies a weaker second half of the year than expected, analysts at Jefferies said.

Persistent inflation and trade uncertainties have caused consumers to avoid non-essential expenses such as dining out, reducing footfall at restaurants.

Although the company's international sales rose 4% from a year ago in the second quarter, in North America, which contributes the majority of revenue, sales were flat at $1.07 billion.

Lamb Weston also faces tariff risks due to its reliance on imported commodities like palm oil, even as prices of raw materials, such as potatoes, have dropped.

The company maintained its annual forecast of $6.35 billion to $6.55 billion, the midpoint of which is below analysts' estimate of $6.52 billion, according to data compiled by LSEG.

It reported revenue of $1.62 billion for the quarter ended November 23, above estimates of $1.59 billion.

The company reported an adjusted profit of 69 cents per share for the second quarter, beating analysts' average estimate of 65 cents per share.

(Reporting by Koyena Das in Bengaluru; Editing by Sahal Muhammed)

((koyena.das@thomsonreuters.com))