Colombia's Juan Manuel Santos and Chinese President Hu Jintao presided over the signing here Wednesday of nine agreements to boost cooperation in a range of industries, including the oil sector.

A pact that Colombian state oil company Ecopetrol inked with the Sinochem conglomerate and the China Development Bank invites the energy-hungry Asian country to participate in a pipeline project linking central Colombia to the Pacific coast.

"Ecopetrol was looking to expand the pipeline network toward the Pacific ... and we issued a call for bids from all interested parties, the Chinese included," the company's transportation vice president, Alvaro Castañeda, said after signing the accord with Sinochem Group President and CEO Liu Deshu.

"We're still in the preliminary and conceptual phase of the engineering development model and we're inviting any international players that want" to join the project, Castañeda said.

Another agreement in principle establishes "long-term strategic cooperation" between Ecopetrol and Sinochem, he added.

In the electricity sector, an agreement in principle was signed between Hydrochina Corp. and Cormagdalena, the government agency tasked with managing the Magdalena River, for the second phase of a project for the use and protection of Colombia's main waterway.

Another document of intent, signed by Colombia's minister of trade, industry and tourism, Sergio Diaz-Granados, and Chinese Commerce Minister Chen Deming, calls for a joint feasibility study for a potential free-trade agreement.

Earlier, Hu met for just over an hour with his Colombian counterpart at Beijing's Great Hall of the People.

The Chinese president expressed his country's desire to promote mutual understanding and diplomatic cooperation "to open new paths within the friendship and collaboration that already unite us," while Santos said he is "convinced that bilateral relations, while already very good, can be much further strengthened."

Bilateral trade exceeded $8 billion in 2011, up from $700 million in 2003, but oil, ferronickel and coal make up 80 percent of Chinese imports from the Andean nation, while Colombia imports Chinese telecommunications equipment, vehicles, appliances and medium technology.

According to news reports in Colombia, China is interested in importing coltan - a vital component in cell phones and computers - from Colombia's Vaupes and Guainia provinces.