A $300 million deal in June 2012 made Larry Ellison the owner of nearly 98 percent of Lanai. The billionaire, however, hasn’t stopped there and has turned to real estate acquisitions on Hawaii’s sixth-largest island.

Since late 2012 a pair of Ellison companies have been buying up homes on Lanai almost two dozen for $40 million, according to property records.

Ellison was already the biggest owner of housing on Lanai, with 455 largely plantation-era rental homes included in the sale of the island by Castle & Cooke Inc.

The new purchases have mostly been luxury vacation homes and condominiums, though some were old plantation housing, including a 502-square-foot house that appeared to be falling down.

Lori Teranishi, a spokeswoman for Ellison’s management company for the island, Pulama Lanai, would not comment on the acquisitions.

Island of Lanai Properties, the real estate brokerage firm Ellison acquired from Castle & Cooke, also would not comment.

Some real estate brokers speculate that a housing shortage on Lanai has prompted Ellison to acquire housing for a team of consultants and employees retained to help execute a vision he has to improve and diversify the island’s economy with projects that include adding a third hotel, a second airport runway, more housing, commercial agriculture, desalinated water production, a research institute, a tennis academy and film studios.

"He has to put up a lot of people here to help him reach his vision," said Sherri Williams, a real estate agent with Hawaii Life who has lived on Lanai for about 10 years. "There’s a huge housing shortage. Ithink it’s that simple."

Other real estate agents are intrigued by Ellison’s housing acquisition spree but are less certain about what’s behind the effort.

"He’s playing his cards close to his chest," said Paul MacLaughlin, an agent with Sotheby’s International Realty on Maui who listed a vacation home for sale three months ago at $6.3 million. The home is next to one Ellison bought in November 2012 for $4.2 million.

MacLaughlin has heard the theory that Ellison is acquiring homes for work personnel, and agrees that it makes sense.

Ellison, however, isn’t just buying and holding homes. One resort condo at The Terraces at Manele that Ellison bought in December for $1.75 million is back on the market for $1.8 million.

Most of the homes Ellison bought after the Castle &Cooke deal are luxury resort condos, including 13 units at The Terraces at Manele acquired for $1.3 million to $2.1 million apiece. The other properties include three luxury resort homes at Manele, a unit in another condo complex called the Palms at Manele and five homes in Lanai City.

Ellison largely has acquired the homes through Lanai Estates LLC, a firm managed by Philip B. Simon, president of an Ellison investment firm. Several other homes also have been bought by another Ellison company, Lanai Resorts LLC.

The billionaire has bought a relatively large number of homes on Lanai, but he is not snapping up everything. There were 100 single-family house and condo sales on Lanai over the past two years, according to the Realtors Association of Maui.

That puts Ellison’s share of transactions at close to 20 percent of the market, which brokers said has helped buoy property values.

Lanai’s real estate market has been recovering with the growing economy but also is depressed somewhat because renovation work on the Manele Bay hotel is holding back some visitor traffic that leads to resort home sales, MacLaughlin said.

MacLaughlin added that demand for vacation homes on the island has grown among prospective buyers who are encouraged by Ellison’s commitment and vision to improve Lanai.

Real estate sales on Lanai have come up dramatically from pretty dismal years as recently as 2010, when there were just seven home sales. That was down from 15 sales in 2009 and 10 in 2008.

Weak resort home sales were among the reasons Castle & Cooke’s billionaire chief executive David Murdock sold Lanai to Ellison. The recession prompted Castle & Cooke to halt speculative resort housing construction and led to an attempt in 2010 to unload unsold inventory of 11 homes at below-market prices at auction.

Developing and selling resort homes represented the economic linchpin of Murdock’s plan to shift Lanai from a pineapple plantation to a luxury resort destination anchored by a pair of Four Seasons hotels, the Manele and the Lodge at Koele, built in the early 1990s.

Murdock obtained permission to build 1,100 homes in the two resort areas 640 at Koele and 460 at Manele. Currently only about 9 percent of the homes roughly 40 units at Koele and 80 units at Manele have been built, according to a recent draft update of the Lanai Community Plan.

Pulama Lanai would not discuss timetables for building more homes. But the community plan update that includes Ellison’s vision calls for expanding Lanai City and other areas on the island for major housing development, including 50 acres near Koele for rural homes, 83 acres near Manele, 76 acres west of Manele for rural homes and 250 acres for up to 50 homes in connection with the proposed new 100-unit hotel at Kahalepalaoa Landing.