PIMCO sees Europe's action on Greece as ineffective in fixing the country's problems, while Britain's sovereign debt rating could be downgraded within a year, a top executive of the world's largest bond fund said.

Scott Mather, head of global portfolio management at Pacific Investment Management Co (PIMCO), told a briefing in Taipei on Thursday that the company was underweighting UK, U.S. and pan-European 10-year sovereign bonds.

Miracles are needed in the next six months in order to keep economic growth in the developed world, Mather said.

PIMCO has been warning investors to stay away from developed countries like Britain with heavy debt burdens, recommending instead shifting assets to Asia and developing countries.

Confidence in Greece as a borrower has been badly shaken by a 300 billion euro ($405 billion) debt pile that exceeds the country's 240 billion euro annual economic output. It has about 23 billion euros worth of bonds -- equivalent to almost 10 percent of its gross domestic product -- maturing between now and the end of May.

Eurozone leaders last week agreed to a joint financial safety net with the IMF to ease Greece's debt crisis and restore confidence in the euro, which has lost 5.5 percent of its value against the U.S. dollar this year.

Mather said, however, that European governments had not said how much money they were going to put into Greece.

Last month, PIMCO said it was maintaining its negative stance on British gilts because the amount of debt the country would have to issue in the future should lead to inflation and a depreciating currency.

Britain's record-high debt has caused disquiet among investors, and Standard & Poor's has put the country's top-notch triple-A rating on a negative watch.

United kingdom