NEW YORK - Another drop in oil prices helped drive the stock market to a loss Thursday, as major indexes gave up their gains from the day before. Chevron, ExxonMobil, and other energy companies led stocks down.

Benchmark U.S. oil sank 70 cents to close at $43.96 a barrel in New York, extending a slump that has slashed prices by more than half over the last year. Brent crude, a benchmark for international oils used by many U.S. refineries, fell $1.48 to close at $54.43 in London.

"Given the big drop that we've had, the big question is, when does oil hit bottom?" asked Jeff Carbone, a senior partner at Cornerstone Financial Partners in Charlotte, N.C. "I don't think oil will bottom out until a company or a country flinches and cuts production. Right now, producers are still pumping as much as they can."

The Dow Jones industrial average lost 117.16 points, or 0.65 percent, to close at 17,959.03.

The Nasdaq composite rose 9.55 points, or 0.19 percent, to 4,992.38.

The Standard & Poor's 500 fell 10.23 points, or 0.49 percent, to 2,089.27.

It was Apple's first day as a member of the Dow. The maker of iPhones, iPads, and other gadgets replaced AT&T. Goldman Sachs, meanwhile, took Visa's title as the most expensive stock among the blue chips. Because the Dow weighs its 30 companies by their share price instead of their market value, a stock split for Visa pushed the payment processor off its perch.

Thursday's economic news gave investors little encouragement to drive stocks up. An index aimed at gauging the economy's momentum rose by a slight amount for a second straight month, and the Labor Department reported that weekly applications for unemployment aid edged up by 1,000, to 291,000 last week.

Phil Orlando, chief equity strategist at Federated Investors, thinks the market could hit a rough patch soon, with the S&P 500 sliding 5 percent or more in the coming months.

"Why do we think that? Because what hit the fourth quarter hit in the first quarter: the stronger dollar, the decline in energy prices, and the weather," Orlando said.

Any turbulence shouldn't last long, he said, arguing that low gas prices could lead to a surge in consumer spending later in the year.

In the commodity markets, gold rose $17.70 to $1,169 an ounce, while silver jumped 57 cents to $16.11 an ounce. Copper added nine cents to $2.66 a pound.

Wholesale gasoline fell 2.5 cents to close at $1.774 a gallon. Heating oil fell 5.1 cents to close at $1.722 a gallon. Natural gas fell 10.7 cents to close at $2.813 per 1,000 cubic feet.