Maui Electric Co. said it has scaled back its request for a rate increase under an agreement reached with the state consumer advocate.

The company, which has about 66,000 customers, is seeking a 3.3 percent increase, down from the 9.7 percent it had sought in its original request filed with the Public Utilities Commission last fall. The revised request would generate annual revenue of $10.3 million compared with $28.2 million in the original request, the utility said.

The majority of the difference is the result of the company’s revising its sales and expenses estimates since the case was filed, Maui Electric said in a filing Monday with the Securities and Exchange Commission.

For example, the company agreed to limit investment in a heat and power system installed at a Maui hotel to $3.5 million. The actual cost of the system was $4.8 million. As a result, the company said it plans to write off $1.3 million of the investment.

The PUC is expected to issue an interim ruling in the case by late summer.

Maui Electric also has a second rate case pending before the PUC. The case, filed in 2007, calls for a 3.7 percent rate increase.