* Says close to acquiring a sapphire asset

* Full-year revenue falls 42 pct

* Full-year pretax loss $22.8 mln vs profit $161.5 mln last year

* Appoints Janet Blas as group CFO

* Shares fall 4 pct

(Adds comments from CEO, analyst; updates share movement)

By Roshni Menon

Oct 3 (Reuters) - Miner Gemfields Plc GEM.L said it would focus on acquiring more emerald deposits as it looks to position itself as the De Beers of international emerald trade.

The company, which produces about a fifth of the world's rough emeralds, reported a 42 percent drop in revenue as it had to push back an auction following a directive by the Zambian government. ID:nRS6C2KcQ

Gemfields, owner of the luxury jewellery brand Faberg, was selling output from its flagship Kagem mine across the world until the Zambian government said in April that all emeralds mined in the country must be auctioned at home.

"Because of some of the problems we've experienced with our emeralds over the last little while, we want to make sure that we're not dependent on any single source and we don't want to put all our eggs in one basket," Chief Executive Ian Harebottle told Reuters.

The company, which was lobbying the Zambian government to extend its emerald auctions beyond the African country, said interactions with the government were "better than they have ever been". ID:nL4N0G33C5

"There is a chance that resolution to the current impasse with the Government of Zambia may be achieved during the year," J.P. Morgan Cazenove analyst Alexander Mees said in a note to clients.

The London-listed miner also said that it was keen to expand into other gemstones and was close to acquiring a sapphire asset.

"I've said it a few times that Gemfields would like a traffic light of coloured stones. So what we'd like is emerald rubies and sapphires - the red, green and blue - and then the rest to piggy-back on that," Harebottle said.

Gemfields reported a pretax loss of $22.8 million for the year ended June 30, compared with a profit of $161.5 million a year earlier, mainly due to costs related to the acquisition of luxury jewellery brand Faberg and higher marketing expenses.

The miner also said it appointed Janet Blas as group chief financial officer, replacing Mark Summers who left the company.

Gemfields bought Faberg, famed for making lavish Easter eggs for Russia's last tsar, in a deal valued at about $142 million last November and appointed Mila Kunis as its brand ambassador in February. ID:nL5E8ML229

Shares in the company were down 3.8 percent at 25.35 pence at 0844 GMT on the London Stock Exchange.

(Reporting by Karen Rebelo and Roshni Menon in Bangalore; Editing by Supriya Kurane)

((karen.rebelo@thomsonreuters.com)(within UK +44 20 7542 1810)(outside UK +91 80 6749 1136)(Reuters Messaging: karen.rebelo.thomsonreuters.com@reuters.net))

Keywords: GEMFIELDS RESULTS/