LONDON (Reuters) -- Oil slipped below $60 on Monday as investors preferred to put money into other commodities as they waited for signs that OPEC members would adhere to their pledge to cut crude supply.

U.S. light crude tumbled $1.05 a barrel to $59.70, almost giving up gains made on Friday.

Brent crude fell $1.27 to $59.81 a barrel.

It will be some time before output cuts by members of the Organization of the Petroleum Exporting Countries have any impact on high crude stocks in the world's largest consumer the United States.

Shipments take weeks to arrive in the U.S. from the Gulf. Until then, investors see potential for more gains elsewhere, said Olivier Jakob of Petromatrix. "Large speculative funds remain more focused on other commodities where the fundamentals are clearer," Jakob said in a report. "Over the next ten days we believe we can drift again towards lower values of the range $57-$64."

Some investors doubt OPEC members will fully adhere to their agreement to cut 1.2 million barrels per day (bpd) from supply from Nov. 1.

To date, OPEC's largest exporter Saudi Arabia and the UAE are the only countries to have informed customers of supply cuts. Refiners who buy crude from other big OPEC producers like Iran and Kuwait say they have yet to see receive notification of the new curbs.

Preliminary data for October planted further doubts among investors on Friday as it showed a small rise in OPEC output. The group's October production was 30.18 million bpd, up from 30.15 in September, consultant Petrologistics said on Friday, despite pledges that month from Nigeria and Venezuela to voluntarily cut back. "We've had some fund selling, the market is still in a bearish frame of mind," said Rob Laughlin, broker at Man Financial. "The jury is out on how much OPEC will be able to manage their cuts. Some members are leading the way, but the market needs more."

Oil rose last week as U.S. crude stocks fell sharply, chilly winter weather kicked in and on concern about supply security from Saudi Arabia. The price has risen over $4 from its 2006 low of $56.55 on Oct. 20.

Higher oil prices over the past several months helped U.S. oil majors including ExxonMobil (Charts), ConocoPhillips (Charts) and Chevron (Charts) all posted earnings that pleased investors last week.

BP (Charts) reported lower profits however, partly due to the shutdown of its Alaska oil field.

Signs of an early or chilly winter in the U.S. Northeast have lent some support to prices, although a Friday forecast by Meteorlogix called for temperatures to return to seasonal norms by later this week, tempering heating fuel demand.

Most projections have called for a normal to colder-than-usual winter. The cold may put heating oil stocks under pressure, although last week stocks were 7 percent higher than a year ago.

Last week's data showed robust demand growth in the United States, but figures out on Monday showed China's implied oil demand rose only 3 percent in September from a year ago, the slowest pace since a contraction in January.