Hawaii’s sixth-largest island, Lanai, has been known by different nicknames through the decades — from the “Pineapple Island” to the “Private Island” and at present “Hawaii’s Most Enticing Island.” One could soon call it “Ellison Island.”

The third-richest man in America, Oracle Corp. co-founder and CEO Larry Ellison, is buying Lanai from fellow billionaire David Murdock for hundreds of millions of dollars in cash, though the exact price was not disclosed.

A sale agreement signed May 2 is scheduled to close Wednesday.

If completed, the purchase would represent perhaps the ultimate trophy property for the software company leader known for his pursuit of fantastic real estate.

Murdock’s company, Castle & Cooke Inc., describes Lanai as the largest privately held island in the United States. It owns about 97 percent of Lanai, including two luxury hotels, two golf courses, a solar farm, commercial buildings, rental housing, water utilities and about 88,000 acres of mostly undeveloped land once largely planted in pineapple.

A transfer of the island to Ellison stands to alter the future of Lanai and holds much uncertainty for its 3,193 residents, many of whom work for Castle & Cooke and would work instead for a company controlled by Ellison after a sale.

Ellison could not be reached for comment Wednesday.

Castle & Cooke, in documents filed with the state, said Ellison intends to bring new investment to Lanai that should reinvigorate tourism, stimulate its economy and create new jobs.

“The buyer anticipates making substantial investments in Lanai and is looking forward to partnering with the people of Lanai to chart the island’s future,” the company said.

Murdock said in a written statement that Ellison possesses the right enthusiasm, commitment and respect for the island and its people, and will be a positive part of the community in the years to come.

“I believe that Larry Ellison will bring a new and fresh perspective to the island and its people,” Murdock said.

Kepa Maly, executive director of the Lanai Cultural Heritage Center, said he hopes Ellison takes a different approach than Murdock, given the island’s valuable history, people and land.

“The David Murdock approach, like most other Western business endeavors on the island, couldn’t come to grips with the reality of living within the wealth and limitations of Lanai’s natural-social environment,” Maly said. “Clearly there is no ‘get-rich-quick scheme’ in the future, or past, for Lanai.”

Ellison, 67, co-founded Oracle in 1977 and leads the tech firm as chief executive. Outside of his job, he is known for passions in racing yachts, playing tennis, flying jets and acquiring real estate.

Lanai could be seen as a asset unlike anything else bought by someone described in an October Wall Street Journal article as “one of the nation’s most voracious consumers of trophy real estate.”

The story said Ellison has spent hundreds of millions of dollars on property since the 1990s, including a 249-acre Rancho Mirage, Calif., estate with a private 19-hole golf course, a historic garden property in Kyoto, Japan, and several home sites around Lake Tahoe, Calif., acquired for about $100 million.

Murdock, 89, also ranks among the wealthiest Americans, with a net worth pegged by Forbes at $2.7 billion. The corporate raider with diverse holdings from transportation-equipment leasing to biotechnology park development has owned much of Lanai for more than 25 years.

Murdock acquired his initial stake when he rescued publicly traded Castle & Cooke, one of Hawaii’s oldest companies, from bankruptcy in 1985 and became chairman and chief executive. In 2000, he acquired the balance of Castle & Cooke for $675 million.

Castle & Cooke’s ownership of Lanai stemmed from an acquisition James Dole made in 1922 to expand his Hawaiian Pineapple Co. Ltd. and establish the world’s largest pineapple plantation.

Under Murdock, Lanai’s economy went through jolts as he uprooted the island’s pineapple industry in favor of luxury resort and housing development that have failed to turn a profit through some boom years and two economic downturns.

Through the years, Murdock has been praised and derided for his control of Lanai, most recently because of plans to develop windmills for producing electricity to transmit to Oahu.

Some observers speculate Murdock decided to sell Lanai because a vocal group of residents oppose his wind energy plan, which he envisioned would allow him to offset past losses and continue to support the island.

However, Murdock is retaining rights to develop a wind project on Lanai.

Murdock didn’t state a motivation for selling, but said he looks forward to the island’s future as a homeowner there.

“Lanai has been my passion for years and I have made huge investments of money, time and energy for the betterment of the island economy and its residents,” he said. “I have enjoyed my time with the many positive people of Lanai and remain forever grateful for the opportunity to have made a positive difference in Lanai’s present as well as its future.”

Murdock said he didn’t make an impulsive decision, and suggested that the right buyer came along at the right time.

Yet in a filing with the state Public Utilities Commission, Castle & Cooke indicated that Murdock needs to sell because he can no longer sustain Lanai’s financial losses.

Murdock has previously reported that the island produced annual losses between $20 million and $30 million from 2006 to 2010.

“While (Murdock) has continued to fund shortfalls in order to mitigate negative impacts to the Lanai economy and employment for residents, (he) can no longer sustain this,” Castle & Cooke said in the filing.

Castle & Cooke is seeking approval from the PUC to transfer ownership of three state-regulated utilities it operates on Lanai. The company is asking for an interim approval by Tuesday  so the sale can close a day later.

The company said the sale could fall apart if its closing date isn’t met. If that happens, finding another buyer could take years, potentially endangering Lanai’s economic future, the filing said.

Henry Curtis, executive director of environmental group Life of the Land, objected to the company’s request because it ignores PUC rules giving the public 20 days to contest a transfer of a privately owned utility.

“Castle & Cooke should not be permitted to bypass the public review process,” he said in a statement.

State Senate President Shan Tsutsui (D-Wailuku, Waihee, Kahului, Paia, Lower Paia) urged Gov. Neil Abercrombie to consider a state purchase of Lanai, given the uncertainty represented by new private ownership of an island with cultural and natural resources.

“The uncertainty that the potential sale represents presents grave concerns of the future of the people of Lanai,” Tsutsui said in a letter to Abercrombie Tuesday. “The continued private ownership of Lanai may prove detrimental to the people of Lanai and the state, as a private owner is not subject to public, community, or government input in making decisions that can and will affect such parties.”

Abercrombie didn’t respond to Tsutsui’s letter, but issued a statement saying he looked forward to welcoming Ellison. “It is my understanding that Mr. Ellison has had a long-standing interest in Lanai. His passion for nature, particularly the ocean, is well known specifically in the realm of America’s Cup sailing. He is also a businessman whose record of community involvement in medical research and education causes is equally notable.”

Maui Mayor Alan Arakawa issued a statement admiring Murdock’s compassion for the people of Lanai and wishing that working with Ellison will lead to good things for the island and its residents.