U.S. crude was off 82 cents at $104.33 by 1150 GMT. Oil had hit a record $106.54 last Friday. London Brent crude was off 78 cents at $101.60.
Fears of recession, following the biggest U.S. job losses in five years and strains in the credit market, have depressed equities and the dollar while prompting many investors to seek safety in commodities including oil.
The effect of the slowdown in the United States, the world's biggest consumer of oil, could start to have an impact on demand.
A sharp drop in U.S. crude oil inventories and OPEC's decision last week to hold supplies steady have also boosted oil prices.
OPEC's president, Chakib Khelil, was quoted on Monday as saying that speculation and political tension would keep prices at triple digits during the current financial year.
Prices could retreat in 2009 with a recovery of the U.S. dollar following the election of a new U.S. president, and as fundamentals reassert themselves, he was reported as saying by government newspaper El Moudjahid and state news agency APS.
The Organization of the Petroleum Exporting Countries, which pumps more than a third of the world's oil, has long argued the current high prices do not reflect market fundamentals and are being driven by speculation.
OPEC will next meet in September, although ministers could confer informally at a conference between consumers and producers in Rome on April 20-22.
Easing tensions between OPEC member Venezuela, a top oil exporter to the United States, and neighbor Colombia, also kept oil price gains in check. The presidents of Colombia, Ecuador and Venezuela ended a border dispute on Friday, after a week of regional diplomacy in the face of hostile rhetoric and troop build-ups.
NYMEX crude has set an intraday record 12 times since January 2, when prices first hit $100. Settlements above $100 have been reached in nine of the last 14 sessions, the latest being Friday's $105.15.