(Repeats item issued earlier, with no change to text)
* OPEC, allies extend production cuts through March 2018
* Investors see ongoing glut, refiners say market may tighten
* Other supplies readily available, from U.S., Russia, Africa
* Rising U.S. oil volumes head to Asia, offset OPEC cuts
SINGAPORE, May 26 (Reuters) - The OPEC-led decision to extend a production cut to March 2018 disappointed financial investors, prompting an exit from oil futures markets, while refiners in Asia were mostly concerned with whether it meant they would need to go hunting for crude.
In Vienna, the Organization of the Petroleum Exporting Countries (OPEC) and some non-OPEC producers on Thursday extended a pledge to cut 1.8 million barrels per day (bpd) of output until the end of the first quarter of 2018.
Financial traders did not like what they heard, thinking it meant an ongoing oil glut. "The market voted with its feet", investment bank Jefferies said, dragging crude futures down 5 percent to near $50 a barrel.
In physical markets, however, where tankers can take weeks or months to deliver up to $100 million in crude oil, refiners want to know if they will be forced to search for new suppliers.
"This is a declaration of a strong will of OPEC as well as non-OPEC producers to tighten overall supply-demand," said Yasushi Kimura, president of the Petroleum Association of Japan, and chairman of petroleum conglomerate JXTG Holdings.
To ensure crude supplies, "we need to carefully monitor OPEC's production cut adherence," Kimura said.
Crude is by far the biggest cost for refiners and the petrochemical industry, shaking margins DUB-SIN-REF whenever benchmark prices take broad swings.
Kimura said the extended cuts could mean demand may exceed supply in 2017, which would be the first time in years.
This would force refiners to start using up reserves, pushing up prices at least until production catches back up with consumption.
"In 2017, global demand is likely to exceed supply ... and crude prices are likely to ... rise towards $60 by the end of the year," JXTG Holdings' Kimura said.
So far, though, the cuts that started in January have barely dented supply in Asia, home to three of the world's four biggest oil consumers.
Exporters were keen to maintain global market share, and they cut domestic supplies or shipments to marginal buyers. As a result, inventories in the big consumer markets have remained bloated, and prices low.
"We have (so far) not had any impact in terms of any cut from any of these (OPEC) sources into India," said B. Ashok, chairman of Indian Oil Corp, the country's biggest petroleum company.
OPEC sources said that will change as top exporter Saudi Arabia especially is keen to see a visibly tighter market.
Many refiners, however, are still not expecting a real crude shortage, largely due to ample alternative supplies.
"Crudes that can be processed in our refineries include crudes from the U.S. We have procured some crude even from Canada. We have been procuring crude from Latin America ... Africa, Russia," Ashok said.
U.S. producers have become a key alternative source of supply as their output - largely due to shale oil - has soared by 10 percent since mid-2016 to 9.3 million bpd C-OUT-T-EIA, close to Saudi Arabia's and Russia's levels.
These producers have been fast to fill OPEC's gap, with an average of 374,000 bpd of crude from the United States coming to Asia in the first four months of 2017, according to data compiled by Thomson Reuters Oil Research and Forecasts.
That compares with an average of just 48,000 bpd in 2016.
"The cut in OPEC supplies will be offset by higher U.S. crude production," said KY Lin, spokesman for Formosa Petrochemical Corp., one of Asia's biggest refiners and petrochemical producers.
Still, most analysts including Goldman Sachs, Jefferies and Barclays, expect prices to gradually rise towards the beginning of 2018 as the market tightens.
While consumers may have to live with higher prices as OPEC and its allies hold back output, the longer the policy lasts, the more the cartel risks losing permanent market share.
"In response to ... OPEC production cuts we are working on diversification of crude oil import sources and looking beyond the Middle East," said Kim Wookyung, a spokeswoman at SK Innovation, owner of South Korea's largest refiner SK Energy.
Reporting Osamu Tsukimori in TOKYO, Niha Dasgupta in NEW DELHI, Li Peng Seng in SINGAPORE, and Jane Chung in SEOUL; Writing by Henning Gloystein; Editing by Tom Hogue