NextEra Energy Inc. has spent more than $21 million on advisers and consultants as the Florida-based energy company works to buy Hawaii’s largest electric utility for $4.3 billion.

NextEra and Hawaiian Electric Industries submitted a list of the consultants, advisers and other third parties the companies have paid to help with the sale in a filing with the Public Utilities Commission, the regulatory agency reviewing the sale.

NextEra needs the approval of the PUC to close on the purchase of HEI. Opposition to the deal has been strong, with all 28 of the official organizations intervening in the PUC case either rejecting the proposal or accepting it only if changes are made. The PUC is conducting public hearings on the sale across the state this month and next.

As of July 31, NextEra Energy has paid several local law firms, communications agencies and consulting agencies, one of which is tied to a state politician.

DTL HAWAII, a strategy studio where state Sen. Donovan Dela Cruz (D, Mililani Mauka-Waipio Acres-Wheeler) is the vice president for communications, received $84,000 from NextEra.

Honolulu-based Bennet Group Strategic Communications, headed by Joan Bennet, was paid $230,000. NextEra paid Honolulu-based Anthology Marketing Group $2,000.

The company also listed Kaimana Hila, a consulting firm owned by Jennifer Sabas, former chief of staff for U.S. Sen. Daniel K. Inouye. Sabas was hired by NextEra in June. The report listed its payment to Kaimana as between $0 and $500.

The University of Hawaii, Maui Economic Development and Maui Native Hawaiian Chamber Foundation also are named, earning $20,000, $15,000 and $8,000, respectively.

NEXTERA PAID Concentric Energy Advisors $513,000. John Reed, chairman and chief executive officer of Concentric Energy Advisors, was one of the key witnesses in NextEra’s rebuttal filing along with Hawaiian Electric Co. CEO Alan Oshima and NextEra Energy Hawaii President Eric Gleason. NextEra paid $832,000 to Morihara Lau & Fong, a Honolulu-based law firm that specializes in public utility regulation, environmental natural resource issues and water rights.

NextEra paid New York-based law firm Wachtell, Lipton, Rosen & Katz $6.65 million, Blackstone Holdings $1 million and New York-based communications firm Joele Frank $1.1 million.

Hawaiian Electric Cos. reported spending $475,000 on transaction costs for advisers, consultants and other third parties as of July 31.