By Tiemoko Diallo

BAMAKO, Feb 13 (Reuters) - Chinese President Hu Jintao laid the first brick of a "Friendship Bridge" in Mali's capital on Friday, calling it China's largest ever gift to impoverished West Africa.

Hu launched the construction project in front of hundreds of drummers, school children and Chinese workers on the second day of an African tour meant to extend trade and investment links with the continent.

The Chinese president then flew to Senegal, the second stop in a tour that analysts say aims to reassure Africa that Beijing will not ease up on aid during hard economic times and its investment interests extend beyond oil and mining.

China has had a long involvement in Africa, building many infrastructure projects in countries that emerged from European colonial rule. But with a booming economy that has been hungry for resources, its interest has diversified and trade with Africa has multiplied 10-fold since 2000, soaring 45 percent to nearly $107 billion last year alone.

"The third Bamako bridge will be the largest project carried out in West Africa paid for with money donated by China," Hu said at a ceremony with Mali's President Amadou Toumani Toure.

Malian government figures put the cost of the 2.6 km (1.6 mile) "Sino-Malian Friendship Bridge" at around 38 billion CFA francs ($74.9 million).

The flood of Chinese interest in Africa has attracted criticism as well as praise on the world's poorest continent.