Liberia has renegotiated the terms of a massive iron ore agreement with the world's largest steel company, Mittal.
Mittal needs Liberia's iron ore for its expansion plans
The original deal had been criticised by lobby group Global Witness, which said it allowed Mittal to opt out of human rights and environmental laws.
Total investment has now been increased to $1bn and the government retains ownership of the port and railway but other details are unclear.
Liberia is trying to recover after years of conflict and corruption.
After taking power this year, President Ellen Johnson-Sirleaf promised to renegotiate the terms of several major deals signed by the transitional government set up at the end of the conflict in 2003.
The BBC's Ledgerhood Rennie in Monrovia says this pledge is very popular.
A Liberian government spokesman said full details of the deal would be published after the government delegation returned to Liberia.
The original Mittal agreement was worth $900m. Mittal says the deal will create 3,500 jobs.
"The prices for minerals will now be based on international standards and practices. There was disagreement in particular on the amount of royalties," a Mittal spokesman told the AFP news agency.
Mittal is planning to almost double in size in the next 25 years and half of the ore needed for that expansion is set to come from Liberia.
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