TOKYO, April 20 Reuters Oil prices fell to their lowest in about three weeks on Thursday, depressed by a firmer dollar and rate hike expectations which outweighed lower U.S. crude stocks.

Brent crude futures were down 1.13, or 1.4, to trade at 81.99 a barrel at 1141 GMT. West Texas Intermediate crude WTI futures dropped 1.04, or 1.3, to 78.12 a barrel.

Both benchmarks, following a 2 fall on Wednesday, are at their lowest since late March, just before a surprise OPEC production cut announcement, although not all gains from that move have been wiped out yet.

Equities markets, which often move in tandem with oil prices, pulled away from multiweek highs and the U.S. dollar index has moved up around 0.3 this week so far, on course for its strongest week since late February.

A strengthening greenback makes oil more expensive for holders of other currencies.

U.S. economic activity was little changed in recent weeks, according to a Federal Reserve report.

A Reuters poll of economists showed the Fed is likely to deliver a final 25basispoint rate increase in May after the most aggressive spate of policy tightening in 40 years.

On the other side of the Atlantic, persistent doubledigit inflation in Britain has bolstered expectations of a further Bank of England rate hike.

Meanwhile, U.S. crude stockpiles fell by 4.6 million barrels as refinery runs and exports rose, while gasoline inventories jumped unexpectedly on disappointing demand, according to the U.S. Energy…