Speaking about the deal, Gamesa CEO Jorge Calvet said the agreement involves researching suitable sites for the joint development of wind farms in international markets.
Calvet said the United States and European and Latin American countries would be the primary target markets.
Under the agreement, signed coinciding with the Spanish Prime Minister's visit to China, Gamesa and Longyuan will research wind projects, both those Gamesa has already identified and included in its wind farm project portfolio, and new ventures in strategic countries.
Xie Changjun, president of Longyuan, said: "In Gamesa, we have found the ideal partner for our growth strategy, thanks to its comprehensive understanding of the business as a technology company and wind farm developer and its experience in the development of wind farms in the world's largest markets."
In 2009, Longyuan signed an agreement with partners from South Africa to develop 1GW wind farms in the country, marking its marches towards the world market. It has 40-50 overseas projects under negotiation covering South Africa, the United States, Hungary, Kazakhstan and Australia, the company said in December 2010.
Calvet said: "Gamesa has carved out a market position as a leader in technology, and we will now offer our know-how for finding potential wind farm sites and for project management of joint ventures in the world's most promising wind markets.
"This agreement with Longyuan represents a qualitative leap in our presence in the wind market, as we become partners in the international expansion of one of the world's top wind farm developers."
Gamesa, the world’s sixth largest wind turbine maker, currently has a wind farm portfolio totaling more than 226GW at varying stages of development in Europe, the Americas and Asia, said Calvet.
Also on Wednesday, Gamesa reached three memoranda of understanding (MoU) with power companies Longyuan, China Resources Power (CRP) and Datang, which may culminate in firm contracts in coming months, to supply turbine capacity of 900MW. And Gamesa agreed to jointly develop 200MW wind farms with Longyuan in China by 2015.
In 2010, China accounted for 28 percent of Gamesa’s total sales, compared with 15 percent in 2009.