China, which holds the world's largest foreign exchange reserves, bought several hundred million euros of Spanish bonds last week as Asian investors returned to the eurozone peripheral market after a two-month hiatus.

China's State Administration of Foreign Exchange, or Safe, which manages the reserves under the country's central bank, were allocated up to €400m ($505m) of Spanish 10-year bonds in a debt deal last Tuesday, according to people familiar with the situation.

Safe had put in an order for about €1bn after demand from investors rose to €14.5bn in a matter of a few hours on Tuesday last week. Mike Amey, portfolio manager at Pimco, said: “The fact big Asian investors are back in the market is a big vote of confidence for the eurozone. There was strong demand for the Spanish bond. It really helped sentiment.”