* Announcement seen soon, after president visits Brasil

* Liberia has attracted $10 billion iron ore investment

(Adds mine launch, comments from Liberia president, China commerce minister)

By Tim Cocks

MONROVIA, April 22 (Reuters) - Liberia is in talks with Brazil's Vale (VALE5.SA) (VALE.N), the world's top iron ore producer, over a possible concession and expects to make an announcement soon, the investment commission said on Thursday.

If it goes ahead, investment commission chairman Richard Tolbert said it would be the sixth major iron ore mining deal awarded to a foreign firm in the past five years, adding to $10 billion worth of agreements already signed.

The deal highlights steps the West African nation has made in restoring stability and attracting investors seeking to tap into vast iron ore reserves in a country that was in a near-permanent state of war between 1989 and 2003.

"As a result of our president's visit to Brazil (this month), we could get the world's number one iron ore company here," Tolbert said in an interview in the Liberian capital.

"I'm not going to go into details but I'm very happy to see (Vale) come in. There will be an announcement coming soon."

China Union (000036.SZ) snatched up an iron ore concession at the start of last year. A delegation of Chinese officials led by Vice Commerce Minister Fu Ziying officially opened the 25-year Bong mine project late on Thursday.

"The Bong mine will hire lots of Liberian workers," Fu told journalists. "China is ready to start the project as soon as Liberian legislators approve it."

That project is expected to cost $2.6 billion, the largest foreign investment in the country since the war.

President Ellen Johnson Sirleaf told Reuters on the sidelines of the launch that she expected benefits of this project to trickle down to ordinary Liberians.

"Before it begins to affect the lives of people in a positive way, it may be a year or so. They have a diversified programme: they're going to do agriculture and generate electricity as well as the mining operation," she said.

In January, Israeli businessman Jacob Engel became the latest foreigner to invest in Liberian iron ore deposits, grabbing a 25-year licence for the Western Cluster of mines with reserves of more than 1.1 billion tonnes of iron ore.

"We are very careful not to give all of our resources to any one investor or country," Tolbert said. "You can see that in the diversity of our mining concessions."

GEARING BACK UP

Vale is eyeing African iron ore deposits as the economic recovery boosts demand for steel, and a delegation from Vale met Gabon's President Ali Bongo this month.

ArcelorMittal (ISPA.AS), the world's largest steelmaker, and No. 1 diversified miner BHP Billiton (BHP.AX) BTL.L also have large concessions in Liberia.

They are currently negotiating to combine their iron ore assets in West Africa to cut costs on infrastructure. BHP has potentially vast deposits in neighbouring Guinea.

ArcelorMittal delayed the launch of its planned $1.5 billion iron ore mine in Liberia last year, owing to a drop in demand for steel because of the global recession.

"They slowed down like everybody else due to the recession, but they did not stop. Now they're gearing back up again. They should be exporting ore by next year," said Tolbert.

The other major iron ore deal is a $2 billion project by Russia's Severstal (CHMF.MM).

Besides iron ore, Jersey-based private AmLib Holdings Plc was due to open a $200 million gold mine soon.

"We've always done alluvial gold mining. They are going to do the first deep rock gold mining here. That's a very major development," Tolbert said. (Editing by Marguerita Choy)