European stock benchmarks gingerly built on four-week highs on Thursday as oil prices rose and the risk of a U.K. "Brexit" appeared to retreat.

A new poll by former Conservative peer and professional pollster Michael Ashcroft found that respondents expected the "remain" camp to win 65% of the vote in the June 23 referendum about whether the U.K. should leave the European Union, with Brexiteers tipped to garner 35%.

But the Office for National Statistics' second stab at U.K. first-quarter GDP figures took the sheen off that market-friendly poll. The ONS confirmed that GDP rose 0.4% quarter-on-quarter, driven by consumer demand, but it trimmed the annual growth rate to 2.0% from 2.1%.

The pound initially rose against the dollar and the euro on Thursday but the U.K. currency later pared gains and was recently worth $1.4705, a rise of 0.05%.

Meanwhile oil broke through the $50 a barrel threshold for first time in nearly seven months, with Brent crude recently trading at up 0.58% at $50.03.

By late morning the major indices were up after struggling to gain direction initially.

The FTSE 100 was recently up 0.11% at 6,269.17, having pared early gains and briefly entered negative territory.

In Frankfurt the Dax was recently up 0.29% at 10,234.72, with steelmaker and industrial machinery maker ThyssenKrupp among the main gainers. And in Paris the Cac 40 was recently up 0.13% at 4,487.34.

Banco Popular Espanol was recently down about 20% in Madrid after the lender announced plans for a EUR2.5 billion ($2.8 billion) rights issue.

In London department store chain Debenhams  was up 1.5% on news it had poached Amazon's (AMZN) - Get Report European fashion head Sergio Bucher as its new CEO.

Retailer Pets at Home was recently up well over 3% after lifting its full-year dividend by 39% to meet a new objective of handing back 50% of earnings.

Computer chip designer and Apple (AAPL) - Get Report supplier Imagination Technologies (IGNMF) shrugged off a profit warning to rise almost 2%. Posting full-year earnings in line with expectations, it said it expects the current year revenue and loss to be "materially below market expectations" after adjusting contracts and writing off debts on two customer orders. But it said an operational review was progressing well and announced it would make interim CEO Andrew Heath the permanent boss.

In Tokyo the Nikkei 225 closed up 0.09% at 16,772.46. The Topix was virtually unchanged at 1,342.87.

Air bags maker Takata  closed up more than 21% on reports that the company has started talks about a potential takeover with suitors including Kohlberg Kravis Roberts  (KKR) - Get Report . The Nikkei said KKR may take a 60% stake.

KKR spokesman Steve Okun declined to comment and Takata also declined to comment.

Takata on Wednesday confirmed it had hired Lazard for advice on a financial restructuring.

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