Jan 23 (Reuters) - Brazilian miner Vale said

on Thursday its subsidiary Vale Base Metals has started a

"strategic review" of its nickel assets in Thompson, Canada,

including their potential sale.

In a securities filing, Vale said it will explore and assess

a series of alternatives for the assets, which include two

operating underground mines and an adjacent mill.

Vale added that the potential sale of the assets are among

the alternatives to be assessed in the review, which it expects

to conclude in the second half of the year.

"The Thompson review is part of a process to optimize

Vale Base Metals' asset base, ensuring the competitiveness of

its vertically integrated nickel portfolio," Vale said.

In a separate statement, Vale Base Metals said the

optimization would enable more copper output in Brazil's Carajas

region.

Vale Base Metals produced some 10,500 metric tons of

finished nickel in the 12-month through last September, Vale

said.