Asia stocks took a breather Thursday after a rally during the previous session, but energy firms were mostly up after oil surged past $50 a barrel for the first time this year.

Investors seemed to brush off another strong lead from Wall Street and Europe, treading softly as the Group of Seven leaders' summit kicked off in Japan, where the sputtering global economy is likely to top the agenda.

Markets had rallied around the world Wednesday as investors welcomed a debt relief deal for Greece, bright German data, easing concerns of a Brexit and firmer oil prices.

Traders were also beginning to adjust to news of a possible US interest rate hike come June or July, analysts said, viewing it as an indication of economic strength.

But on Thursday morning Hong Kong was down 0.3 percent after surging by 2.7 percent during the previous session, while Shanghai dropped 0.9 percent.

Sydney, Seoul and Taipei were all flat, but Tokyo was up 0.3 percent by the break and Manila tumbled 1.3 percent.

Energy firms again saw some of the biggest gains after oil passed $50 a barrel in Asia for the first time in months on the back of data overnight that showed a fall in US crude inventories, adding to expectations of a tightening global market.

In its weekly report, the Department of Energy said that US commercial crude oil inventories fell by 4.2 million barrels in the week to May 20.

“The immediate driver is a good draw on US crude stockpiles, helping to nudge the price up a bit further,” Ric Spooner, a chief analyst at CMC Markets in Sydney, told Bloomberg News.

“The market hasn’t had any bad news to knock it off its perch but the price is likely to struggle if it gets into the $50s. There is still quite a bit of inventory around.”

- G7 summit kicks off in Japan -
At around 0330 GMT, Brent North Sea crude for July delivery was up 33 cents at $50.07 a barrel while US benchmark West Texas Intermediate was trading 29 cents higher at $49.85.

In Sydney, WorleyParsons soared 7.1 percent and BHP Biliton was 2.4 percent higher, while in Hong Kong, CNOOC added 2.2 percent and Sinopec increased nearly one percent. 

Tokyo-listed Inpex also jumped more than three percent and JX Holdings advanced 1.6 percent.

Also in Japan, world leaders began two days of G7 talks, with heads of state and government from the United States, Britain, France, Germany, Italy, Canada and host Japan all present.  

Markets will no doubt be eyeing the talks for further trading cues as leaders discuss the global economy, with divisions likely to remain over whether the world should spend or save its way out of its current malaise, with Japan and Germany at odds over the issue.

China, the world's second largest economy, will not be present but looks set to loom large over discussions. 

Elsewhere, New Zealand said Thursday its budget was back in the black but warned a British exit from the European Union could derail the strong economic performance Wellington expects over the next few years. 

"The possibility of Britain exiting the European Union may lead to high volatility in global markets," the papers said, adding this "would weigh on demand and inflation in New Zealand".

- Key figures around 0330 GMT -

Tokyo: Nikkei 225: UP 0.29 percent at 16,805.63 (break)

Shanghai - Composite: DOWN 0.9 percent at 2,789.359

Hong Kong - Hang Seng: DOWN 0.3 percent at 20,315.37

Euro/dollar: UP at 1.1184 from $1.1161 on Wednesday

Dollar/yen: DOWN at 109.70 yen from 110.10 yen

London - FTSE 100: UP 0.7 percent at 6.262,85 points (close)

New York - Dow: UP 0.8 percent at 17,851.51 (close)