By Justin Scheck 

LONDON--Royal Dutch Shell PLC said Thursday it would curb its planned spending over the next three years by some $15 billion, freeze dividends at current levels and scale back shale investments world-wide to cope with weaker oil prices.

Shell, the first of the four giant, integrated oil companies to announce quarterly results, had higher profits compared with a poor year-prior quarter. But earnings were below some analysts' forecasts, driving shares down nearly 5% in London trading.

"The macro environment has moved against us," Shell Chief Executive Ben van Beurden said in a Thursday news conference. He and Chief Financial Officer Simon Henry said Shell is cutting costs but continuing some big investments--including a potential $1 billion-plus exploration project in Alaska's Arctic this year. Shell forecasts rebounding oil prices in coming years, and Mr. van Beurden said, "It's very important not to get into a slash-and-burn mentality."

Quarterly profit on a current-cost-of-supplies basis--which factors out the impact of inventories and is similar to the net profit reported by U.S. oil companies--was $4.16 billion, compared with $2.15 billion a year earlier. For the full year, the current-cost-of-supplies profit was $19.04 billion, up 14% from 2013.

Oil prices have fallen more than 50% since the middle of last year, weighing on the entire industry. ConocoPhillips reported a quarterly loss Thursday, and more struggles will come--the average Brent crude price last quarter was about $77, Barclays said in a report this week, but prices have since dropped below $50.

Shell by many measures didn't show a year-over-year decline last quarter, largely because issues including high spending and poor refining margins depressed its year-earlier earnings. That prompted the company to issue its first profit warning in a decade.

Mr. van Beurden said Shell would spend less on capital investment in 2015 than 2014, when it spent $37.3 billion. He said Shell has backed away from prospective projects to cut its planned capital investment through 2017 by $15 billion.

Mr. Henry said that if it gets U.S. government approval, Shell plans to revive its Arctic-exploration push, which encountered weather-related delays and problems including the grounding of an in-transit drill ship at the beginning of 2013.

Bernstein Research analyst Oswald Clint said Shell's profits disappointed investors partially because of losses in the North American shale business, which includes resources in the areas where the fracking boom has helped produce today's oil glut.

Mr. van Beurden said Shell is re-evaluating shale properties world-wide and may divest assets outside North America. Shell has shale properties in places such as Argentina, Turkey and China's Sichuan basin. "The pace of development outside North America is slower everywhere than people thought it would be," Mr. Henry said in a Thursday interview.

Shell said it would pay a fourth-quarter dividend of 47 cents per ordinary share, a 4% rise on the same quarter last year but flat from the third quarter. Mr. Henry said that "over the past three months, it's become increasingly obvious" that Shell couldn't raise its dividend in the near term with oil prices falling. He said the board completed its decision this week.

Investors in big oil companies have come to expect rising dividends. The firms have been reluctant to cut payouts, and in some recent quarters have borrowed money to fill the gap between cash flow and spending on dividends and capital investment. Now, "dividend growth is going to slow" across the sector, said Brian Youngberg, an analyst with Edward Jones.

Shell said earnings in its exploration-and-production division were $2.65 billion for the quarter, up from $1.85 billion a year earlier. But excluding one-off items like write-downs and income from divestments, income in the division declined by 30% from a year earlier, to $1.73 billion in the quarter. For the full year, earnings in the division were up 25% from 2013, to $15.84 billion.

Shell said its production for the quarter was 3.21 million barrels per day of oil and equivalent natural-gas volumes, down 1% from a year prior. Full-year production was 3.08 million barrels of oil and natural-gas equivalents per day, down 4% from 2013.

Shell's processing, or downstream, business reported earnings of $1.54 billion for the quarter, up from $472 million a year earlier. For the full year, Shell's downstream earnings were $3.41 billion, down 12% from 2013.

Revenue for the quarter was $92.37 billion, down from $109.24 billion a year earlier. Shell's 2014 revenue was $421.11 billion, down from $451.24 billion in 2013. Net income for the quarter fell to $773 million from $1.78 billion; for the year, net income dropped 8% to $15.05 billion.

Rory Gallivan contributed to this article.

Write to Justin Scheck at justin.scheck@wsj.com

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