A flurry of oil companies slashing upstream spending has raised expectations production growth could soon ease.

An ongoing strike that began February 1 affecting nine US refineries and chemical plants has also supported refined products.

The United Steelworkers union rejected an offer Thursday from US refiners, extending the labor action that has so far only shut Tesoro's 160,000 b/d refinery in Martinez, California (See story, 1701 GMT).

Analysts remain divided whether the downturn in oil prices is over.

"The market needs to see a drumbeat of bearish news to drive prices lower, but I haven't concluded that we've bottomed yet," Tradition Energy senior analyst Gene McGillian said.

"I think the market will trade lower, just not in a straight down scenario like after Thanksgiving [2014]," he said.

OPEC members decided November 27 to hold the group's output ceiling at 30 million b/d, setting in motion a steep selloff.

A softer dollar and optimism around Chinese demand aided oil futures Thursday. The People's Bank of China cut its reserve ratio to 19.5% from 20%, a move designed to inject liquidity into the banking system.

The US dollar index was down, hovering around 93.5. The euro gained against the dollar, trading at approximately $1.40.

"The euro is rallying on speculation that the Swiss national bank is intervening in currency markets to weaken the Swiss franc, hence the see-saw of lower dollar/rising crude," Schneider Electric analyst Matt Smith said in a note.

The European Union also revised upward its economic growth forecast at 1.3% in 2015 and 1.9% in 2016, another factor behind the euro's rise, Smith said.

The dollar nonetheless remains close to multi-year highs. A strong dollar makes greenback-denominated commodities, like oil, more expensive and puts downward pressure on prices.

US Energy Information Administration data showed Wednesday crude stocks building to a record-high 413 million barrel. "So if oil can rebound even in the aftermath of one of the most bearish reports in history at least by supply standards is it possible that the market is looking beyond the glut?" Price Futures Group analyst Phil Flynn asked in a note Thursday.

Other analysts disagree, saying a global surplus will continue weighing on prices until production falls from OPEC or non-OPEC suppliers.

Top OPEC producer, Saudi Arabia, has pledged to defend market share from rising non-OPEC producers.

On Thursday, finance minister Ibrahim Abdulaziz Al-Assaf said the kingdom would be able to cope with low oil prices for "quite some time" because of its vast financial resources and its "huge" ability to borrow on international markets (See story, 1150 GMT).

In an interview with CNBC, Assaf said oil markets moved up and down in cycles and that Saudi Arabia had built up financial buffers in preparation for a period of lower prices.

OPEC's crude exports, excluding those from Angola and Ecuador, are expected to average 24.21 million b/d over the four weeks to February 21, up 340,000 b/d from the previous four-week period, UK-based tanker tracker Oil Movements said Thursday.

--Geoffrey Craig, geoffrey.craig@platts.com
--Margaret McQuaile, margaret.mcquaile@platts.com
--Edited by Derek Sands, derek.sands@platts.com