LONDON (Reuters) - Leading investors around the world barely changed their exposure to assets in August, trimming equities slightly in favor of bonds, where they loaded up on top-notch corporates, Reuters polls showed on Tuesday.

The surveys of 54 top investment houses in the United States, Britain, Europe ex UK and Japan showed a shift in different regions of the world.

U.S. and European investors cut back on equities, while British and Japanese investors increased their exposure.

But the overall tone was one of continued caution.

Concern was expressed about the slowing U.S. economy and the danger of it slipping back into recession.

“Uncertainty about the U.S. economic outlook has intensified,” said Yoshinori Nagano, a senior strategist at Daiwa Asset Management.

“If the U.S. economy actually slows down then this would affect Europe and would also make it difficult for emerging economies to maintain their high growth,” he said.

Equity holdings fell to 50.4 percent of a mixed asset portfolio in the month from July’s 50.6 percent, although investors said their stance remained mildly overweight. Bonds rose to 36.3 percent from 36.0 percent and cash was unchanged at a relatively high 5.8 percent.

One key finding was the continued move by investors into investment grade credit.

The polls showed 27.4 percent of a bond portfolio now held investment grade corporate debt, up from 22.6 percent a month earlier. Exposure to other categories of bonds slipped.

Andrew Milligan, head of global strategy at Standard Life Investments, said the August move probably reflected a search for yields as government bonds are now offering so little. But he said his firm has long been a fan.

“In a world of low interest rates, low inflation and uncertainty about the future of corporate earnings, we have focused on the secure returns of investment grade,” he said.

REGIONALLY

U.S. fund managers cut their exposure to equities in August and raised their bond allocations.

The survey of 14 U.S.-based fund management firms found an average of 61.5 percent of assets held in equities, compared with 65.0 percent a month earlier.

Exposure to bonds, rose to 31.8 percent in August from 29.8 percent in July. Cash allocations moved to 3.1 percent in August, from 2.0 percent in July.

European fund managers cut their equity holdings to their lowest level in a year and lifted bonds and cash.

The poll of 16 Europe-based asset management firms outside of Britain showed 45.1 percent in equities, down from 46.8 percent in July. They held 41.2 percent in bonds compared with 40.6 percent last month. Cash holdings stood at 6.9 percent, compared with 6.7 percent last month.

The survey of 11 British fund managers showed the average exposure to equities jumped more than 3 percentage points from a month earlier.

The average allocation to equities climbed to 49.8 percent in August, compared with 46.4 percent in July. Allocations to bonds fell to 24.2 percent from 25.5 percent.

The effect was exaggerated by a change in the sample, but the trend was the same on a like-for-like basis.

Japanese fund managers raised their weighting for equities to a four-month high in August and cut their weighting for bonds for a second straight month to the lowest since March.

The 13 fund management companies in the poll raised their average allocation for equities to 45.2 percent in August from 44.2 percent in July. The bonds weighting dropped to 47.9 percent from 48.2 percent the previous month.

A fifth poll of Chinese fund managers, not included in the global survey, showed an increase in the recommendation for stock exposure to a five-month high.