The Arizona Corporation Commission Tuesday unanimously voted to approve the sale of Tucson Electric Power's parent company to Canada-based Fortis, Inc.

The purchase of UNS Energy will cost Fortis $4.3 billion, which includes the assumption of $1.8 billion in debt.

“For our customers, they should not see any difference," said Joseph Barrios, a TEP spokesman. "Tucson Electric Power will remain TEP. Our focus will continue to be on providing safe, reliable service to our customers. We’ll maintain headquarters here in Tucson.”

Barrios added that TEP customers will see one added benefit, a small deduction from their electric bills from October through March each of the next five years.

The "acquisition credit" will be between $1 for residential customers and $200 for larger scale commercial users. It is meant to show the Corporation Commission a concrete way that the sale will positively affect utility customers.

Barrios also said the new parent company should help TEP in its future plans for expansion and efforts to produce more green energy by providing more funding for the improvements.

The deal is expected to be completed by the end of August.