More than half of investors believe that it is highly possible at least one country will leave the eurozone next year, according to a latest Barclays survey.

The Global Macro Survey Q2 edition, released on Monday, showed that 58 percent of investors interviewed expect at least one country to leave the single-currency area next year, an increase of 19 percentage points from March.

And 50 percent of respondents believe an exit would be confined to Greece.

While the risk of a quick Greek exit dwindled after the pro-bailout New Democracy Party won Greece's parliamentary elections on Sunday, it is still uncertain whether the party would succeed in forming a coalition government and fixing the country's economic woes.

Such uncertainties were evident when shares in major European stock markets pared early gains after Sunday's election. Italian and Spanish shares plunged nearly 3 percent.

"There would be difficulties ahead for the Greek economy, whether they are part of the euro or not part of the euro. But I believe the challenge will be more successfully met if they continue to be part of the euro," Robert Diamond, Barclays Plc Chief Executive Officer, told Xinhua shortly before Greece's weekend elections.

"The underpinnings of the single currency are very strong," Diamond said, adding that it is in the interest of both Greece and Europe for the southern European country to stay within the euro zone.

Barclays has no direct exposure to Greece and the market is more prepared than six or 12 months ago, said Diamond. However, "in some area of Europe, both governments and banks were slow to react relative to the U.S. and Britain. So I think it's fair to say that there're more changes to come across for continent Europe and the financial services industry."

As for China, Diamond was optimistic. The Chinese economy hit bottom in May and June, and would register a growth rate of around 8 percent this year despite external headwinds, he said.

Barclays' survey showed that 64 percent of foreign exchange and equity investors viewed the euro area as a key risk to the global economic recovery, a ratio nearly doubling that in March.

The survey also indicated that U.S. prospects are relatively strong. Nearly 80 percent of credit investors considered U.S. credit as the most attractive, 17 percent up from March.