ORLANDO, FLA. -- The time-share resort industry, for years plagued by low-quality products and high-pressure sales, is moving into the mainstream as profits lure giant corporations into the act.

"It's taking years to live that {shady} image down," said Dennis Hof, who is involved in developing the 525-villa Dolphin's Court at Sea World. In a significant change from the the 1970s and 1980s, the time-share industry today is increasingly dominated by large corporate players, Hof said.

"The major players today produce quality resorts and market them in a professional manner without high pressure and gimmicks," said Hof, executive vice president of Euroactividade U.S. "There's no need for gimmickry with a good product."

Major corporations already in the time-sharing business -- the sale or leasing of resort condominiums by time periods, generally in weekly increments -- include Marriott Corp., Shell Oil Co., Hilton Hotels Corp. and International Telephone and Telegraph Corp. The next heavyweight company expected to join the game is Walt Disney Co.

The potential for huge profits caught the big players' eyes. Time-share weeks frequently sell for between $9,000 and $15,000. A two-bedroom condominium -- comparable to a unit that might sell for $100,000 -- could generate five times that much revenue if 50 weeks are sold at an average of $10,000.

Because of Disney and other theme-park attractions, Central Florida is one of the world's top time-share locations. Euroactividade, a major European developer of time-share resorts and second homes, recently recognized the area's status by making Orlando its U.S. headquarters. The company has its corporate headquarters in London and Zurich.

Stephany Madsen, vice president of the American Resort and Development Association, a Washington-based trade association, said there's no question that the movement of big corporations into time-share development has increased the industry's credibility.

"They research it in great detail before making the move and tend to set new standards that are good for the consumer," she said.

State regulation also helped. Florida tightened its controls over the industry in the early 1980s to curb deceptive marketing practices and to provide consumer protections.

As the infant industry grew in the 1970s, unscrupulous developers began converting and selling such properties as run-down "mom-and-pop" beach motels. Consumers were lured with sweepstakes in which prizes such as luxury automobiles were offered as inducements to tour resorts and hear sales pitches. The actual prizes often amounted to little more than cheap jewelry.

While government regulation and the entry of more responsible players have greatly improved the business in recent years, some developers still employ questionable sales methods, said Mark Pacala, a Disney Development Co. vice president overseeing the move into time-share resorts.

"Some {developers} do an excellent job {of marketing}, but we've been surprised at some of the sales practices still going on in some places," Pacala said. "In the '90s the industry needs to come to grips with that."

Disney intends to set the pace in developing quality and marketing integrity, he said.

Some details still are being worked out -- such as whether the resort will be on an ownership or a right-to-use basis -- but Disney expects to be in the time-share resort business in 1991, Pacala said.

"We're looking at very new, bold approaches to providing people with vacations," he said.