NEW YORK
-- Shoppers at Wal-Mart stores across America are loading carts with merchandise - maybe a flat-screen TV, a few DVDs and a six-pack of beer - and strolling out without paying. Employees also are helping themselves to goods they haven't paid for.

The world's largest retailer is saying little about these kinds of thefts, but its recent public disclosures that it is experiencing an increase in so-called shrinkage at its U.S. stores suggests that inventory losses due to shoplifting, employee theft, paperwork errors and supplier fraud could be worsening.

The hit is likely to rise to more than $3 billion this year for Wal-Mart Stores Inc., which generated sales of $348.6 billion last year, according to retail consultant Burt Flickinger III.

Flickinger and other analysts say the increase in theft may be tied to Wal-Mart's highly publicized decision last year to no longer prosecute minor cases of shoplifting in order to focus on organized shoplifting rings. Former employees also say staffing levels, including security personnel, have been reduced, making it easier for theft to occur. And a union-backed group critical of the retailer's personnel policies contends general worker discontent is playing a role.

Wal-Mart declined to offer any explanations for the rise in losses, but denied it has cut security staff and said employee morale is rising rather than falling.

Although Wal-Mart declined to reveal any details, analysts suspect Wal-Mart - which for years had a theft loss rate that was half that of its peers - is getting closer to the industrywide average. Theft is a big problem for all retailers, costing them $41.6 billion last year, according to a joint study released Tuesday by the National Retail Federation and the University of Florida. The study found that the theft rate as a percentage of sales ticked upward slightly to 1.61 percent of sales in 2006 from 1.60 percent in 2005.

Whatever the cause, such theft - which late founder Sam Walton once called one of retailers' top profit killers - adds one more challenge when Wal-Mart is already struggling with sluggish sales at its established stores due to an overall economic slowdown as well as its own stumbles in its home and apparel merchandising strategies.