Prime Minister Manmohan Singh [Images] on Tuesday left for India, after his three-day maiden visit to China, during which he held talks with the country's top leadership and received a pledge from Beijing [Images] on bilateral cooperation in the field of civil nuclear energy.

Before leaving, Singh had a meeting with Chinese President Hu Jintao as well as the Chairman of the National People's Congress Wu Bangguo. On Monday, he had met his Chinese counterpart Wen Jiabao.

"Our talks were held in an atmosphere of sincerity, warmth and friendship. They were constructive and forward looking. This gives me cause for optimism for the future of our ties," Singh said after meeting Wen.

During Singh's visit, the two sides signed 11 agreements for cooperation in rail, housing, geo-sciences, land resource management and other sectors, besides a shared vision for the 21st century of both countries.

On the sidelines of the Prime Minister's visit, the Special Representatives of the two countries on the boundary issue, National Security Advisor M K Narayanan and Chinese Vice Foreign Minister Dai Bingguo, held informal negotiations in Beijing.

Singh also addressed scholars at the prestigious Chinese Academy of Social Sciences, elaborating on bilateral relations, regional and international issues as well as India's foreign policy.