* Brent crude futures struggle to stay above $50 per barrel
* Norway oil strike to have limited impact on production
* Nigeria's output rises on tentative ceasefire
* But production in U.S., Iraq falls
By Henning Gloystein
SINGAPORE, June 30 (Reuters) - Oil prices fell in early trade on Thursday, with Brent futures struggling to defend $50 per barrel as fears over strike outages in Norway faded and as Nigeria's production improved.
International Brent crude oil futures LCOc1 were trading at $50.10 per barrel at 0126 GMT, down 51 cents, or 1 percent, from their last settlement. U.S. West Texas Intermediate (WTI) crude futures CLc1 were down 38 cents, or 0.76 percent, at $49.50 a barrel.
Traders said the lower prices were a result of an improving supply outlook.
Initial fears of sharp production cuts from a looming strike by Norway's oil and gas workers seemed to ease as output from the North Sea's biggest producer would only fall by about 7 percent even in case of a walk-out, according to data from Norway's Petroleum Directorate. Nigeria, violent attacks on the oil infrastructure knocked out some 600,000 barrels of daily oil production to around 1.25 million barrels per day (bpd) between January and mid-June. But a tentative ceasefire means output has recovered by 200,000-300,000 bpd since then.
"If sustainable, this ceasefire would pave the way for higher output, with the government optimistically aiming for a return to normal production by end-July," Goldman Sachs (NYSE:GS) said, although it added that there was a risk of attacks resuming.
Prior to the disruptions, Nigerian production stood around 2 million bpd.
Goldman Sachs also said that production outages from Canadian wildfires since May, which peaked around 1.5 million bpd, would recover over the coming months and virtually end by September.
In other regions, however, there were signs of a tightening market.
The U.S. Energy Information Administration reported on Wednesday that crude stockpiles fell 4.1 million barrels in the week to June 24, the sixth consecutive week of drawdowns, to 526.6 million barrels.
U.S. crude oil production was at 8.62 million bpd, down from a peak of over 9.6 million bpd in June 2015.
In the Middle East, OPEC's second biggest producer Iraq is set to see output fall for a second straight month in June.
Iraq's seaborne exports in the first 29 days of June have averaged 3.14 million bpd, according to loading data tracked by Reuters and an industry source. That would be down 60,000 bpd from May. (Editing by Joseph Radford)