(Reuters) -U.S. holiday sales are expected to grow as much as 3.5%, the slowest pace in six years, the National Retail Federation forecast on Tuesday, as shoppers turn more frugal and get picky with spending on non-essentials.

Holiday sales are set to rise between $979.5 billion and $989 billion from November to December, the retail industry group (NRF) projected. That compared to 3.9% growth to $955.6 billion last year.

Retailers are expected to hire between 400,000 and 500,000 seasonal workers this year, compared with 509,000 in 2023, the group said.

NRF remains optimistic about the pace of economic activity and growth projected in the second half of the year, said NRF Chief Economist Jack Kleinhenz.

"We expect consumers will continue to be more price conscious and pragmatic in their spending decisions, looking for discounts and better value for holiday goods, as still-high interest rates and lingering inflation in some categories continues to be on their minds," NRF CEO Matthew Shay said.

Consumers are limiting their spending and opting for cheaper alternatives for categories ranging from groceries to apparel, forcing companies to lower prices and offer more discounts.

Online and other non-store sales are expected to expand up to 9% to $297.9 billion, compared with $273.3 billion in 2023, as per the retail industry group's forecast.

A shorter holiday season, with only 26 days between Thanksgiving and Christmas, has forced retailers including Walmart, Target and Amazon, as well as China's Shein and PDD Holdings' Temu, to introduce early deals.

Deloitte has also forecast 2024 holiday sales to grow at their slowest pace in six years due to cautious shopping.

(Reporting by Anuja Bharat Mistry in Bengaluru; Editing by Sriraj Kalluvila and Alan Barona)