China's leaders have begun a meeting where the economic and political agenda for the next decade will be discussed.
In a brief report announcing that the four-day meeting had opened in Beijing, state news agency Xinhua said it would discuss "major issues concerning comprehensively deepening reforms".
Areas expected to be discussed include liberalising the financial sector, state-owned enterprises and reforming China's household registration system. The talks are held behind closed doors.
The meeting is being closely watched after senior Communist Party official Yu Zhengsheng said last month that "unprecedented" economic and social reforms would be discussed at the meeting.
A report released by the Development Research Centre of the State Council, a state-affiliated think tank, has called for three broad areas and eight key sectors for reform, the BBC reports.
The plan, known as the 383 plan, called on leaders to liberalise the market, encourage innovation and competition, and increase government transparency.
However, as the meeting is being held in secret, experts say its impact may not be apparent until much later. Analysts do not expect any political reforms to be discussed.
Third Plenums refer to the third time new leaders of China lead a plenary session of the Central Committee.
They generally take place a year after new leaders take office, after they have established their power base.
Previous Third Plenums have had a major impact on China's development.
At the Third Plenum in 1978, former leader Deng Xiaoping announced the opening-up of China's economy, spearheading major market-oriented reforms.