* US output proving resilient, global demand slowing

* Opec output could rise further in 2016

* Chances of Opec/non-Opec deal very low

* Stock building to continue into second half of 2016

The world will store unwanted oil for most of 2016 as declines in US output take time and Opec is unlikely to cut a deal with other producers to reduce ballooning output, the International Energy Agency said.

The agency, which coordinates energy policies of industrialised countries, said that while it did not believe oil prices could follow some of the most extreme forecasts and fall to as low as $10 per barrel, it was equally hard to see how they could rise significantly from current levels.

The Paris-based IEA trimmed its forecast for 2016 oil demand growth, which now stands at 1.17mn barrels per day (bpd) following a five-year high of 1.6mn in 2015.

It cut its call on Opec crude for 2016 by 100,000 bpd to 31.7mn bpd. That figure is much lower than Opec's January output of 32.63mn bpd.

"Persistent speculation about a deal between Opec and leading non-Opec producers to cut output appears to be just that: speculation. It is Opec's business whether or not it makes output cuts either alone or in concert with other producers but the likelihood of coordinated cuts is very low," the IEA said.

Oil prices collapsed over the past 18 months to below $30 a barrel from as high as $115 as Opec opened its taps to drive higher-cost producers such as US shale companies out of the market.

Low oil prices have spurred global demand but it was not enough to absorb all crude produced. As a result, unwanted oil went into storage, leading to record global stockpiles of over 3bn barrels.

US shale oil output has started to decline because of low prices and Opec has said it sees the market rebalancing sometime later in 2016 when demand finally meets supply.

But the IEA said supply may still exceed demand throughout the whole of 2016 and added it saw non-Opec output falling by just 0.6mn bpd in 2016.

"The number could be higher of course and many senior international oil company figures have said so but there is a lingering feeling that the big fall-off in production from US shale producers is taking an awful long time to happen. Perhaps resilience still has some way to go," the IEA said.

The agency also said it saw the dollar remaining strong as it benefits from its safe-haven status, meaning more downward pressure on oil prices.

With weaker global oil demand, likely new gains in Iraqi, Iranian and Saudi output, low chances of an Opec deal, resilient US production and a strong dollar - the IEA said the global oil glut was only poised to worsen.

It said that even if Opec production remained flat, global stocks would build by 2mn bpd in the first quarter, followed by a 1.5mn-bpd build in the second quarter.

"Supply and demand data for the second half of the year suggests more stock building, this time by 0.3mn bpd. If these numbers prove to be accurate, and with the market already awash in oil, it is very hard to see how oil prices can rise significantly in the short term. In these conditions the short-term risk to the downside has increased."