Feb 2 (Reuters) - Chinese President Hu Jintao pledged 40 million yuan ($4.8 million) in humanitarian aid for Darfur on Friday while visiting Sudan on his eight-nation African tour. He also wrote off up to $70 million in Sudanese debts and signed economic deals including a 100 million yuan interest-free loan for Sudan to build a new presidential palace. Here are some key facts about Chinese-African deals and relations: TRADE RELATIONS: * Trade links between fast-growing economic powerhouse China and Africa have taken a leap forward since 2004, when President Hu Jintao announced a drive to strengthen relations with the energy- and mineral-rich continent. * China's exports to Africa rose in that year by 36 percent year-on-year to $13.82 billion, while imports, mostly natural resources, surged 81 percent to $15.65 billion, according to Chinese figures. -- In 2005, total trade between Africa and China surged again, to $40 billion. -- In 2006, trade between China and Africa reached $55.5 billion, a jump of 40 percent on the previous year. -- Africa now supplies a third of China's crude oil imports. China imported over 14 million barrels of Sudanese oil in 2006. * NOTABLE ENERGY/TRADE DEALS: Jan/Feb 2004 - Total Gabon signs a contract with China's Sinopec under which Gabonese crude oil will be sold to China for the first time. June 2004 - Chinese Vice-President Zeng Qinghong visits Tunisia, Togo, Benin and South Africa. Zeng's trip to South Africa included a deal opening the way for the export of South African citrus to China and letters of intent for two big trade and investment projects. January 2005 - Angola says it plans to use a $2 billion loan from China to repair its infrastructure. China added another $1 billion to its oil-backed loan in March 2006. July 2005 - China and Nigeria sign an $800 million crude oil sale deal between Petrochina International and the Nigerian National Petroleum Corporation (NNPC) to supply 30,000 barrels of crude oil per day to China. January 2006 - China's top offshore oil producer CNOOC agrees to pay $2.3 billion for a stake in a Nigerian oil and gas field, its largest ever overseas acquisition. April 2006 - Algeria awards contracts estimated at $7 billion to Japanese and Chinese consortiums to build parts of a 1,300-km (800-mile) highway running from Tunisia to Morocco. April 2006 - Hu wraps up an Africa tour by concluding an offshore exploration deal with Kenya. The pact allows China's state-controlled CNOOC to explore in six blocks covering 115,343 sq km (44,500 sq miles) in the north and south of Kenya. -- Two days earlier Beijing struck a $4 billion deal for drilling licences in Nigeria, including grants for economic and technical cooperation, anti-malarial medicine and rice. May 2006 - Angola's state-run oil company Sonangol announces Sinopec has won a 40 percent stake in a relinquished part of its lucrative offshore oil Block 18 after proposing a $1.1 billion government signature bonus out of a total investment amounting to more than $1.4 billion. June 2006 - Beijing says it will give $35 million for building West Africa's biggest theatre in Senegal, in a major forays into high art in Africa. Beijing has also announced debt relief for Senegal worth 160 million Yuan ($20 million). Nov. 2006 - China and Africa sign 16 agreements worth a total of $1.9 billion. The deals between 12 Chinese firms and 11 African governments and companies, followed Hu's pledge offering $5 billion in loans and credit, and doubling aid by 2009. Jan. 2007 - China says it will lend Africa $3 billion in preferential credit over three years and double aid and interest-free loans, ahead of Hu's latest tour of Africa. -- On the first leg Hu signs eight accords with Cameroon and cancels its debt to China pledging nearly $100 million. Feb. 2007 - Hu arrives in Liberia and signs agreements to donate anti-malarial drugs, cancel more than $10 million in debt owed to Beijing, and waive duties on Liberian exports to China. He also agrees to projects worth $25 million over two years to help Liberia rebuild after the 1989-2003 civil war.