U.S.-based fund managers cut their average stock holdings to a five-month low in March and held their highest average position in cash since December, as Russia's move into Crimea spooked global markets, a Reuters poll showed.

It was the second straight month that fund managers have lowered their equity holdings in global model portfolios, suggesting investors do not expect the market to continue a rally that pushed the benchmark Standard & Poor's 500 index up nearly 30 percent in 2013.

"What we're seeing is that more investors are taking risk off the table. I know I am," said Alan Gayle, a fund manager at RidgeWorth Investments, who oversees approximately $400 million in assets.

Gayle has been adding to his short-term bond positions due to a combination of rising geopolitical risk in the wake of Russia's expansion into Crimea and a brutal winter in much of the United States that has cut into corporate profits and home sales, he said.

"Investors are putting a lot of pressure on the economy to deliver in the second quarter and it may be challenging for the economy to live up to expectations," he said.

The benchmark Standard & Poor's 500 fell 1.3 percent on March 13, pushing the index into a loss for the year.

The market staged a slight rebound since, giving it a year to date gain of less than 1 percent. By this point last year, the S&P 500 was already up over 8 percent for the year, according to Thomson Reuters data.

Geopolitical tensions have put a sizeable dent into analysts's forecasts for stock market gains, a separate Reuters poll conducted earlier this month showed.

Overall, the average equity holding in global portfolios dipped to 56.0 percent of assets from 56.2 percent the month before, while bond positions fell to 35.3 percent of assets from 35.5 percent.

Cash levels rose to 4.1 percent, their highest since the start of the year. Cash was the only asset class that saw an increase in March.

The poll of 12 fund management firms was conducted between March 12 and March 28.

Within equity portfolios, the largest declines came in euro zone stocks, which fell from 15.2 percent of stock portfolios to 14.7 percent. The largest gain came among U.S. and Canadian companies, which ticked up to 67.2 percent of assets, the highest level since November.

Model bond portfolios were static, although average recommended allocations to sovereign debt rose to its highest in six months while allocations to high-yielding bonds fell.