Royal Dutch Shell Plc reported a 33 percent increase in quarterly earnings on Thursday, beating analyst forecasts despite impairments of almost $2 billion after producing more liquids and selling at higher prices.

The Anglo-Dutch oil company also raised its quarterly dividend and said the value of its share buybacks and dividends for 2014 and 2015 would exceed $30 billion. The stock rose 3 percent in early trade.

Shell's second-quarter earnings on a current cost of supplies basis excluding one-time items were $6.1 billion, up 33 percent from a year earlier. Analysts had expected earnings of $5.46 billion.

"The upstream number was good and the downstream number was better than expected," said Jason Kenney, analyst at Santander, referring to Shell's two largest divisions. "Although downstream was still a weak number."

"Across the business there are some very material writedowns. There may be even more writedowns to come," said Kenney, who has a "hold" rating on Shell's shares.

The quarter's earnings included a net charge of $1 billion after tax with impairments of $1.943 billion related mainly to gas assets in the United States.

The company joins rival BP Plc in reporting better-than-expected earnings.

Chief Executive Ben van Beurden is aiming to improve returns through selling assets and more selective project choices after a rare profit warning issued in January.

Shell announced a second-quarter 2014 dividend of $0.47 per ordinary share, up 4 percent year on year and in line with analyst forecasts.

Global oil companies including Shell have struggled to boost their production in recent years, due in part to declines at existing fields and delays with new projects.

Shell's oil and gas output in the quarter equalled 3.077 million barrels of oil equivalent per day (boepd), up from 3.062 million a year earlier. Some analysts had expected a decline.

Van Beurden, in a statement, said there was room for further improvement.

"Our financial performance for the second quarter of 2014 was more robust than year-ago levels," he said. "But I want to see stronger, more competitive results right across the company, particularly in Oil Products and North America resources plays.