PORTLAND, Ore. — Portland General Electric has asked state utility regulators to approve a 5.6 percent rate increase.

The utility asked for the increase, which would effectively provide $100 million in new revenue, to go into effect next January, The Oregonian/OregonLive reported Thursday. PGE says the increase in necessary to cover increased costs for transmission upgrades and other investments to enhance grid reliability.

"We understand the impact price increases have on our customers, and we do not make this request lightly," PGE chief executive Jim Piro wrote in a news release. "These are important investments that will meet our customers' expectations for safe and resilient service."

The rate case is a 10-month process in which the company will try to justify the request and other stakeholders will try to get regulators to lower the increase.

The request comes after rate increases in 2014, 2015 and 2016 that collectively raised rates about 7 percent.

The proposed raise would vary by customer class, with residential customers seeing a 7.1 percent raise. An average customer using 820 kilowatt hours a month would see their electricity bill increase by $7.30, to about $105, the company said.

Small businesses and commercial customers would see rates go up 5.7 percent and 4.2 percent, respectively.

Ratepayer advocates will likely oppose the rate hike, citing the increases in recent years.

Bob Jenks, executive director of the Citizen's Utility Board of Oregon, said his organization will be calling for PGE to justify why residential customers are bearing the brunt of the increase.

Information from: The Oregonian/OregonLive, http://www.oregonlive.com