President Bush signed into law Tuesday legislation extending a trade pact offering duty-free treatment on some goods and other trade benefits to the poorer countries of sub-Saharan Africa.

"By reducing barriers to trade, this law has increased export, created jobs and expanded opportunity for Africans and Americans alike," Bush said of African Growth and Opportunity Act (search), extended under the bill by seven years to 2015.

During the 15-minute signing ceremony in the Executive Office Building, Bush also called for an end to the conflict in the Darfur (search) region in Sudan (search) "for the sake of peace and basic humanity."

In Darfur, the largely Arab Janjaweed militia has attacked the region's mostly black farmers. Up to 30,000 people have been killed and 2 million are said to be desperately short of food and medicine, including 1 million who have been displaced or become refugees.

"For the sake of peace and basic humanity ... I call upon the government of Sudan to stop the Janjaweed violence," Bush said. "I call on all parties of the conflict to respect the cease-fire, to respect human rights, and to allow for the free movement of humanitarian workers and aid."

The president said the African trade measure "has given American businesses greater confidence to invest in Africa, and encouraged African nations to reform their economies and governments to take advantage of the opportunities."

According to the office of the U.S. Trade Representative, imports under the African Growth and Opportunity Act reached $14 billion in 2003, up 55 percent from the previous year. U.S. direct investment in sub-Saharan Africa was up 12 percent at the end of 2002 to $8.9 billion.

Thirty-seven of the 48 countries of sub-Saharan Africa qualify under the act. Last December, President Bush added Angola while removing two countries — the Central African Republic and Eritrea — for failing to meet eligibility criteria.

The legislation also grants a three-year extension to a provision of the 2000 act, set to expire Sept. 30, that allows African participants to sell duty-free to the United States textiles made from yarn and fabrics coming from third countries.

"The enactment of this law will help ensure that this mutually beneficial trade continues," Bush said. "Trade and investment from around the world is essential to world peace."

The signing was witnessed by ambassadors from African nations, members of Congress who worked on the legislation and others involved in U.S. policy on Africa.

"The Africa trade bill means less poverty in Africa, and it also creates jobs in America," said the Rev. David Beckmann, president of Bread for the World. But he added that Congress and the president still need to honor promises America has made to increase health and development assistance to Africa.