* Consumer price index increases 0.1 percent in October
Core CPI rises 0.2 percent; up 1.8 percent year-on-year
* Retail sales gain 0.2 percent; core sales rise 0.3 percent
By Lucia Mutikani
WASHINGTON, Nov 15 (Reuters) - U.S. consumer prices barely rose in October as the boost to gasoline prices from hurricane-related disruptions to Gulf Coast oil refineries was unwound, but rising rents and healthcare costs pointed to a gradual buildup of underlying inflation.
Low inflation is, however, helping to underpin consumer spending. Other data on Wednesday showed an unexpected increase in retail sales last month as heavy price discounting by automobile manufacturers lifted purchases of motor vehicles.
Rising retail sales and steadily firming underlying price pressures likely will keep the Federal Reserve on course to raise interest rates next month.
The Labor Department said its Consumer Price Index edged up 0.1 percent last month after jumping 0.5 percent in September. That lowered the year-on-year increase in the CPI to 2.0 percent from 2.2 percent in September. The increases were in line with economists' expectations.
Gasoline prices fell 2.4 percent after surging 13.1 percent in September, which was the largest gain since June 2009. September's jump in gasoline prices followed Hurricane Harvey, which struck Texas in late August and disrupted production at oil refineries in the Gulf Coast region.
Food prices were unchanged after nudging up 0.1 percent in September. Excluding the volatile food and energy components, consumer prices rose 0.2 percent in October amid a pickup in the cost of rental accommodation, healthcare costs, tobacco and a range of other goods and services.
The so-called core CPI gained 0.1 percent in September. October's increase lifted the year-on-year increase in the core CPI to 1.8 percent. The year-on-year core CPI had increased by 1.7 percent for five straight months.
The slight pickup in the monthly core CPI could offer some comfort to Fed officials amid concerns that stubbornly low inflation might reflect not only temporary factors but developments that could prove more persistent.
The Fed's preferred inflation measure, the personal consumption expenditures (PCE) price index excluding food and energy, has consistently undershot the U.S. central bank's 2 percent target for more than five years. The Fed has lifted borrowing costs twice this year and has projected three rate increases in 2018.
Prices of U.S. Treasuries fell and the U.S. dollar pared losses against a basket of currencies after the data. U.S. stock index futures extended losses.
RENTS, HEALTHCARE COSTS RISE
Last month, owners' equivalent rent of primary residence climbed 0.3 percent, quickening after September's 0.2 percent increase. The cost of hospital services increased 0.5 percent and prices for doctor visits rose 0.2 percent. There were also increases in prices for wireless phone services, airline fares, education and motor vehicle insurance.
Prices for used cars and trucks rose 0.7 percent, ending nine straight months of declines. New motor vehicle prices, however, fell for a second consecutive month as manufacturers resorted to deep discounting to eliminate an inventory overhang.
In a separate report on Wednesday, the Commerce Department said retail sales increased 0.2 percent last month. Data for September was revised to show sales jumping 1.9 percent, which was the largest gain since March 2015, rather than the previously reported 1.6 percent advance.
Retail sales increased 4.6 percent on an annual basis.
Economists polled by Reuters had forecast that retail sales would be unchanged in October. The slowdown in retail sales last month from September's robust pace largely reflected an unwinding of the boost to building materials and gasoline prices after recent hurricanes.
Receipts at auto dealerships increased 0.7 percent after soaring 4.6 percent in September, supported by the deep price discounting by manufacturers. Sales at gardening and building material stores fell 1.2 percent last month after surging 3.0 percent in September.
Receipts at service stations decreased 1.2 percent in October. That followed a 6.4 percent gain in September. Excluding automobiles, gasoline, building materials and food services, retail sales increased 0.3 percent last month after climbing 0.5 percent in September.
These so-called core retail sales correspond most closely with the consumer spending component of gross domestic product. Last month's increase in core retail sales indicated a healthy pace of consumer spending at the start of the fourth quarter.
Consumer spending, which accounts for more than two-thirds of U.S. economic activity, increased at a 2.4 percent annualized rate in the third quarter. (Reporting by Lucia Mutikani; Editing by Paul Simao)