Public Utilities Commission Chairman Randy Iwase said he has his sights set on June 2016 for the final decision on the sale of Hawaiian Electric Industries to Florida-based NextEra Energy Inc.

“We hope to have a decision by June, but there is no guarantee,” Iwase said in a phone interview Thursday.

PUC approval of the $4.3 billion sale of HEI is needed before NextEra can buy the state’s three largest utilities: Hawaiian Electric Co. on Oahu, Hawaii Electric Light Co. on Hawaii island and Maui Electric Co.

On Wednesday HEI shareholders approved the sale, with the owners of 76 percent of outstanding shares voting in favor. Hawaii law required at least 75 percent approve the sale.

Iwase said he expects a long review due to the historical significance of selling the state’s largest electrical utility.

“We’re hoping for June,” Iwase said “Given the amount of documents and evidence we have to review, we are going to be deliberate on this. This is unusual in its historical significance with Hawaiian Electric up for sale, with the number of parties involved and the number of issues. It is going to take a while to review all of that.”

The sale would move control of Hawaii’s major electrical company to the mainland for the first time since it was founded in 1891 by King David Kalakaua.

Selling HEI attracted a record number of interested parties. Twenty-nine groups were approved by the PUC to be part of the agency’s review of the deal as intervenors.

The discovery process, in which the groups get to request information from HEI and NextEra, will end in August, Iwase said.

Iwase outlined the PUC’s timeline for review, which includes meetings for the public to comment followed by a formal case hearing for the intervenors.

“We are going to go out and hear the public,” Iwase said. “We are going to go to the six major islands.”

Iwase said the PUC will host the “public listening sessions” from September to October. The PUC will hold one meeting on five of the six islands and two on the Big Island — one in Hilo and one in Kona.

At the end of November the PUC plans to begin what it calls the contested case hearings, similar to a court trial. Iwase said the PUC has reserved 15 days at a venue for the 31 groups — the 29 intervenors and the applicants — to participate in the hearings.

“It’s a trial you see in courts. It’s a evidentiary hearing. The parties are called to testify. They can cross-exam. They can introduce evidence,” Iwase said. “Every party has the right to cross-examine the witness.”

The public is allowed to attend the case hearings, unless a party asks to have it closed, Iwase said.

“We make a decision then,” Iwase said.

If the hearings are not concluded by the end of the 15 days, the hearings could be extended. If they are not concluded in December, there would be a recess during January, Iwase said.

After the hearings, the PUC will allow the parties to file closing briefs before the PUC’s final review.

“We probably would give them 30 days,” Iwase said.

Also Thursday, HEI reported details of the Wednesday shareholders vote.

The owners of approximately 84 percent of total outstanding HEI shares participated in the vote.

A total of 90,489,276 shares were voted out of 107,416,201 outstanding shares, according to an HEI filing with the U.S. Securities and Exchange Commission.

A total of 81,207,342 shares voted for the sale, and 7,423,525, or 7 percent, of outstanding shares voted against. Of the voted shares, 1,858,409 abstained from (did not vote for or against) NextEra’s purchase of HEI.

The owners of about 16 percent, or 16,926,925 shares, did not vote.

The shareholder approval does not affect the PUC review, Iwase said.

“That doesn’t affect us at all,” Iwase said “That was a threshold that HECO had to meet.”