Oil prices slipped on Thursday following three days of gains, with the prospect of rapidly dwindling demand due to coronavirus travel bans and lockdowns offsetting hopes a U.S. $2 trillion emergency stimulus will shore up economic activity.

Brent crude LCOc1 futures fell 19 cents, or 0.7%, to $27.20 a barrel by 0441 GMT, Reuters said.

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West Texas Intermediate (WTI) crude CLc1 futures fell 37 cents, or 1.5%, to $24.12 a barrel. Both contracts are down about 60% this year.

The U.S. Senate on Wednesday overwhelmingly backed a $2 trillion bill aimed at helping unemployed workers and industries hurt by the coronavirus epidemic.

But with demand fast contracting and output rising, the outlook for oil remains dim.

IHS Markit estimated global oil demand will contract by more than 14 million barrels per day (bpd) in the second quarter, leading to unprecedented inventory builds.

"Expect fundamental pressure concentrated over March and April, an eight-week blitz period over which stocks currently stand to build north of 1 billion barrels cumulatively," said Roger Diwan, vice president of financial services at IHS Markit.

At the same time, the collapse of a supply-cut pact between the Organization of the Petroleum Exporting Countries and other producers led by Russia, known as OPEC+, is set to boost oil supply, with Saudi Arabia planning to ship more than 10 million bpd from May.

Oil stocks are already rising with tanks around the world filling fast despite a 50%-100% jump in lease costs, as oil companies and traders scramble to park unwanted crude and refined products.