NEW YORK (CNN/Money) - Shares of entertainment powerhouse Disney Co. rose sharply higher on Wednesday after an analyst said positive tourism trends in Orlando, Fla., could lead to an upside surprise in the company's second-quarter results.

But AOL Time Warner, one of Disney's major media rivals, plunged as much as 8 percent, reaching lows not seen since December 1998, as investor concerns about the company's growth prospects intensified after the head of its flagship Internet unit was replaced Tuesday.

Siebel Systems shares also dropped after a brokerage cut its estimates on the software maker, while Akamai Technologies benefited from a deal with Microsoft.

Disney (DIS: up $0.98 to $24.05, Research, Estimates). Lehman Bros. said in a research note that airline traffic and hotel indicators in Orlando, Fla., home to Disney World, "continue to point to a positive rebound" for the park. It said that March hotel occupancy in the city was down 1.2 percent compared with a year earlier, versus a 6.5 percent decline in February and a 9.2 percent drop in January.

Tommy Hilfiger (TOM: up $1.40 to $15.90, Research, Estimates). The fashion house said it was repurchasing up to $125 million worth of its 6.50 percent notes, which are guaranteed by Tommy Hilfiger Corp., in an effort to reduce the company's interest expense.

Akamai Technology (AKAM: up $0.40 to $4.17, Research, Estimates). The Webcasting company got a boost from news of a deal with Microsoft.Net.

Sears Roebuck (S: up $2.98 to $54.18, Research, Estimates). The department store chain said it anticipates a first-quarter profit of 93 cents per share, better than the 61 cents analysts are expecting it to earn and the 45 cents earned one year earlier.

Sonus Networks (SONS: up $0.12 to $2.71, Research, Estimates). The networking equipment maker reported a first-quarter loss of 7 cents a share that was narrower than expected but worse than the breakeven results posted one year earlier. The company also said it will cut all salaries by 10 percent and that second-quarter revenue should be unchanged from the first quarter.

Cooper Tire & Rubber (CTB: up $2.13 to $23.15, Research, Estimates). The tiremaker raised first-quarter guidance, saying it now expects to earn between 35 cents and 37 cents per share, up from the current forecast of analysts for earnings of 30 cents per share.

Asbury Automotive (ABG: up $2.60 to $18.00, Research, Estimates). The auto retailer, which went public March 14, expects to report first-quarter earnings that exceed current estimates by 10 percent. Analysts have projected earnings of 29 cents on a per-share basis. The company also said it is comfortable with 2002 estimates.

Cisco Systems (CSCO: up $0.73 to $15.55, Research, Estimates). UBS Warburg and Merrill Lynch said speculation the network equipment maker might not make its quarterly targets was overdone, and that Cisco should meet expectations.

IDEC Pharmaceuticals (IDPH: up $3.76 to $61.70, Research, Estimates). The biotech developer, a producer of cancer treatments, said first-quarter results would come in better than expected.

AOL Time Warner (AOL: down $1.15 to $20.70, Research, Estimates). Merrill Lynch issued a note on the media company and parent of CNN/Money, saying that Tuesday's move to replace the head of its Web unit may signal that operating trends within the AOL business may be even weaker than expected.

Siebel Systems (SEBL: down $2.12 to $25.44, Research, Estimates). SoundView Technologies cut its 2002 and 2003 revenue and earnings-per-share estimates, as well as its 12-month price target, on the producer of customer relationship management software to reflect increasing evidence of near-term spending constraints. The firm also said that Siebel should be able to meet estimates in the first quarter.

Oracle (ORCL: down $0.43 to $11.55, Research, Estimates). The business software maker was under pressure after CEO Larry Ellison, speaking at a company conference, declined to comment on when corporate technology spending is likely to pick up, and said that he assumed things would probably not get better in the next three months.

Nautica Enterprises (NAUT: down $0.94 to $14.99, Research, Estimates). The apparel maker warned that fiscal fourth-quarter earnings per share will be either a penny or 2 cents per share, below analysts' estimates of 9 cents. For 2002, the company sees earnings of either 76 cents or 77 cents per share, missing estimates of 84 cents.

WorldCom Group (WCOM: down $0.66 to $4.77, Research, Estimates). The telecom service provider continued to sell off sharply on the previous session's weakness in the sector and on concern about a possible restatement of results.

Tier Technologies (TIER: down $2.38 to $14.20, Research, Estimates). The information technology consultant said it would sell its money-losing Australian operations and book a charge due to the sale.

Xerox (XRX: down $0.34 to $9.94, Research, Estimates). The Securities and Exchange Commission has expanded its probe of the copier maker by investigating two former executives and the company's auditor, KPMG.

Research in Motion (RIMM: down $3.07 to $20.19, Research, Estimates). Despite reporting fourth-quarter results that edged higher than analysts' estimates, the maker of the Blackberry handheld communications device warned that its loss for the fiscal first quarter and all of the new year would be wider than expected. UBS Warburg downgraded shares to "hold" from "buy."  

-- from staff and wire reports