Hurricane Frances (search) threatens to dampen sales, and possibly earnings, for a slew of companies — from insurers to airlines — as business activity screeches to a halt only three weeks after Hurricane Charley hit Florida.

When Charley hit last month, Wal-Mart Stores Inc. (WMT) closed about 75 stores. The world's biggest retailer cited the hurricane as one reason for disappointing August sales.

Insurance companies this week tallied their losses from Charley, and Apartment Investment and Management Co. (AIV) cut its third-quarter outlook, citing property damage.

For retailers and airlines, the timing of the storm — expected to hit land Saturday — could not be much worse. Labor Day weekend is one of four long weekends retailers count on for big sales, and the time when they showcase their fall and winter clothing.

But retailers that sell food and home improvement tools may benefit after the storm clears.

Home Depot Inc. has already seen strong demand as Florida residents prepared for the storm. Lumber was selling rapidly at stores in areas where Frances is targeted to reach land. Generators ran short days ago.

Labor Day weekend is also typically strong for travel. The hurricane will probably cost U.S. airlines about $35 million to $40 million, according to Michael Boyd, an aviation consultant at the Boyd Group.

"It will be a more significant hit on airlines that are heavily focused on Florida, like American Airlines, JetBlue and AirTran," Boyd said.

Raymond James analyst James Parker expects a third-quarter loss from AirTran Airways compared to his previous expectation for a profit of 4 cents, citing the storm.

Jacquee Polak, a spokeswoman for Walt Disney Co.'s (DIS) Disney World, said this was "typically one of the bigger times of the year." Disney evacuated its campground on Thursday and Friday but has no plans yet to shut the resort, which closed for half a day when Charley swept through.

Schwab Soundview cut its earnings forecast for the media company, citing the impact of Charley and the potential damage from Frances, as well as waning consumer confidence.

While Hilton Hotels Corp. (HLT) has evacuated properties around Miami under orders from the state, a spokeswoman said hotels in many other parts of Florida were open and pretty much full.

Allstate Corp. (ALL), the largest publicly traded insurer in Florida, was among many insurers tallying losses from Charley this week. Analysts said damage from this storm could match — if not exceed — that created by Charley.

In a research note, UBS analyst Michael Lewis said Frances could even exceed the insured losses of Hurricane Andrew, the most costly U.S. storm in history with insured losses in 2004 dollars that surpassed $20 billion.

"There is no precedent for two category four hurricanes hitting landfall in one hurricane season," said Mark Saunders, lead scientist at University College London's Tropical Storm Risk group. "The last time Florida was hit by two category three storms in the same year was in 1950."

Transportation disruptions included grounded airplanes, interrupted rail service and bottlenecks on roads and at sea. But the holiday weekend might limit the impact on delivery companies such as United Parcel Services Inc. (UPS) because they were not scheduled to deliver packages on Monday.