* No short-term production impact, says Hydro
* Alunorte is world's largest alumina refinery
* Plant has storage capacity for two weeks' output (Adds spokesman, detail, shares)
OSLO, April 1 (Reuters) - Loadings of alumina out of Norsk Hydro's Alunorte plant in Brazil have been stopped after local authorities suspended the environmental operational licence of the plant's port, the Norwegian company said on Tuesday.
Alunorte, situated in the northern state of Para, is the world's largest alumina refinery, with installed capacity of 6.3 million tonnes. The suspension had not affected production at the plant, Hydro said.
Alumina, or aluminium oxide, is used to make aluminium.
The plant has storage capacity of two weeks' worth of production and spokesman Halvor Molland said the stoppage would have no significant effect in the short term.
"This is a case we are trying to solve quickly," he added.
Molland could not say at what point Hydro would be unable to fulfil its delivery commitments. The last loading at the port was on Monday.
Shares in Hydro were down by 0.44 perecnt at 0850 GMT, against a 0.3 percent decline for the Oslo benchmark index .
The Para state environmental authority says that Norsk Hydro's measures to reduce emissions of alumina dust during loadings do not comply with the conditions for the operational licence.
Hydro disagrees with that view and says it uses "one of the best available technologies for alumina loading".
"Alunorte will continue its dialogue with SEMA (The Pará State Environmental Secreteriate) and expects that the matter will be resolved and that the loading of alumina will resume without affecting production", Hydro said in a statement. (Reporting by Ole Petter Skonnord; Editing by David Goodman)