Hawaiian Electric Industries reported an increase in fourth-quarter net income that was largely driven by a one-time factor at the company’s electric utility that depressed earnings in the same quarter a year earlier.

HEI earned $39 million, or 39 cents a share, during the October-through-December quarter, up from $13.8 million, or 14 cents a share in same period in 2012, the company reported Tuesday.

The year-earlier quarter included a $24 million write-down related to rate relief the company granted to its utility customers as part of an agreement negotiated with the state Division of Consumer Advocacy. Excluding the write-down, HEI’s net income would have been $38.3 million in the fourth quarter of 2012.

Hawaiian Electric Co., which operates utilities on Oahu, Hawaii island and in Maui County, reported net income of $32 million in the fourth quarter, up from $4.2 million in the same quarter a year earlier. After adjusting for the write-off, net-income in the year-ago quarter was $28.7 million.

The HEI earnings included results from the company’s American Savings Bank subsidiary, which were reported on Jan. 30.

American Savings Bank showed strong loan growth in the fourth quarter, but net income fell 15.2 percent primarily due to lower gains on residential mortgage sales and less fee income the bank collected from debit card transactions.

The state’s third-largest bank said it earned $12.2 million compared with $14.4 million in the year-earlier quarter.

For all of 2013, HEI earned $161.5 million compared with $138.7 million in 2012. Adjusting for the write-down, earnings in 2012 were $163.1 million.

The financial results were released after the market closed. HEI shares closed down 2 cents at $24.46 on the New York Stock Exchange.