(Bloomberg News) Allocations in U.S. stocks almost doubled in April on renewed concern that the euro-area debt crisis will worsen, prompting investors to sell European equities and hoard cash, a Bank of America Corp. survey showed.

A net 27 percent of 191 respondents, who together manage $554 billion, said they were overweight U.S. stocks, meaning they hold more than is represented in benchmarks. That's up from 14 percent last month. Expectations for an appreciation in the dollar hit the third-highest level in over 10 years.

The U.S. "is a default for investors," said Gary Baker, BofA's head of European equity strategy at a press briefing in London. "If you're concerned about growth, and not sure how concerned you should be, ultimately the U.S. is still your safest haven."

The Standard & Poor's 500 Index has climbed 8.9 percent this year, boosted by better-than-expected U.S. economic data and corporate earnings. The Stoxx Europe 600 Index has risen 5.1 percent so far in 2012. Most U.S. stocks rose yesterday after retail sales climbed 0.8 percent, almost three times as much as economists projected.

Asset allocators reduced their holdings in the euro area this month, with a net 32 percent underweight the region, the survey showed. That's up from 14 percent in March. Investors also reduced their positions in emerging-market equities, to roughly equal that of the U.S.

"There is nothing particularly alarming in the survey," said Baker at the press conference. "It's more precautionary risk reduction than a genuine risk-off scenario. There is a lot of cash sitting on the sidelines."

Cash Balances

The average cash balances for respondents jumped to 4.7 percent in April from 4.2 percent, the highest level since December as investors rotated out of equities and commodities amid renewed sovereign-debt concerns, the survey showed. Baker says cash levels now flash a so-called contrarian buy signal for stock markets.

"Historically, global equities tend to rally 5 to 6 percent in the subsequent four weeks," Baker wrote in the report. "We believe any significant upside in April and May requires stronger growth or fresh policy stimulus."

Overall equity allocations fell to 26 percent overweight from 33 percent last month, while weightings on commodities declined to 8 percent from 10 percent. The survey's Risk & Liquidity Indicator, which combines readings of risk appetite, investor time horizons and cash weightings, fell to 38 from 42, the lowest level since the end of 2011.

BofA conducted the global survey from April 5 to April 12.