By Georgi Kantchev 

LONDON--Oil prices posted gains on Friday but analysts were cautious that a sustained recovery is unlikely until there are more signs of production cuts in the oversupplied global market.

Futures have been moving largely sideways in recent weeks, fluctuating between gains and losses, which some market watchers have interpreted as the prices finally finding a bottom. Oil has shed close to 60% of its value since midsummer on a toxic combination of ample global supplies, lackluster demand for the commodity, and a strong dollar.

Brent crude for March delivery was up $0.26, or 0.6%, at $49.40 a barrel on London's ICE Futures exchange. On the New York Mercantile Exchange, light, sweet crude futures for delivery in March recently traded at $44.92 a barrel, up 0.8% from Thursday's settlement.

"The fall in oil prices will have an effect on supply and there are signs that production will be cut in the future," said Thina M. Saltvedt, senior oil analyst at Nordea Bank Norge. "But until we see those cuts, it's too early for a serious rebound. There is still a lot of oil floating around."

Oil majors have announced spending cuts in recent weeks to cope with the price rout. Royal Dutch Shell said Thursday it would curb its planned spending over the next three years by some $15 billion and scale back investments in shale. ConocoPhillips also said it will slash its capital budget as the company reported losses in the fourth quarter of last year.

"Shell was the first of the oil majors to report yesterday and, if its results are representative of what is going on in the industry as a whole, the outlook is not pretty," Bill McNamara, an analyst at Charles Stanley, said in a report.

Even if oil prices have steadied in January and are projected to rise later in the year as global supply reacts to the lower price environment, analysts are skeptical about the strength of the rebound.

Russ Koesterich, managing director and chief investment strategist at BlackRock, said in a report that "oil prices are likely to stabilize and rise over the long term, but this will not be immediate. Nor is the rise likely to take prices back to the upper end of the previous range."

Meanwhile, Saudi Arabian King Salman bin Abdulaziz has ordered major changes to his government including a cabinet shuffle, but decided to keep veteran oil minister Ali al-Naimi in place.

Mr. Naimi, long one of the most influential oil-price brokers in the global market, was the main strategist behind the decision by the Organization of the Petroleum Exporting Countries to keep its oil output steady in a bid to protect the cartel's market share against booming U.S. shale production. That decision, taken at OPEC's November meeting in Vienna, has further accelerated the slide in prices.

The slump, however, is good news for the global economy, reducing gas prices at the pump and providing a boost to economic growth for net importers of oil.

Barclays estimates that the halving in crude prices in the past six months, if sustained for the whole of 2015, would mean a transfer of $1.6 trillion from oil-producing to oil-consuming countries.

Nymex reformulated gasoline blendstock for February--the benchmark gasoline contract--was little changed at $1.3540 a gallon, while ICE gasoil for February changed hands at $478.75 a metric ton, up $5.25 from Thursday's settlement.

Eric Yep in Singapore contributed to this article.

Write to Georgi Kantchev at georgi.kantchev@wsj.com

Access Investor Kit for Royal Dutch Shell PLC

Visit http://www.companyspotlight.com/partner?cp_code=P479&isin=GB00B03MLX29

Access Investor Kit for Royal Dutch Shell PLC

Visit http://www.companyspotlight.com/partner?cp_code=P479&isin=GB00B03MM408

Access Investor Kit for Royal Dutch Shell PLC

Visit http://www.companyspotlight.com/partner?cp_code=P479&isin=US7802591070

Access Investor Kit for Royal Dutch Shell PLC

Visit http://www.companyspotlight.com/partner?cp_code=P479&isin=US7802592060

Subscribe to WSJ: http://online.wsj.com?mod=djnwires