New York's main contract, light sweet crude for January, fell 20 cents to $87.80 a barrel in the afternoon.
Brent North Sea crude for delivery in January slipped 12 cents to $90.57.
Oil prices "dipped a little this morning but this is after very strong gains yesterday", said Chen Xin Yi, commodities analyst with Barclays Capital in Singapore.
Crude on Thursday rose to its highest level in three weeks supported by strong performances in US retail and pending home sales, with Brent crude breaking past 90 dollars after gaining more than two percent.
But Chen said pessimism over the US employment situation was dampening the markets ahead of the release of a jobs report in the world's largest oil consumer later Friday.
"Broader macroeconomic data has an influence and most recent US data has been mixed, with initial jobless claims worse than expected," she added.
Experts predict November's report will show a jobless rate stuck at 9.6 per cent for the fourth consecutive month, as millions of Americans struggled to get back to work.
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