Chinese authorities have asked Ping An Insurance Group to take a controlling stake in embattled Country Garden, the nation's biggest private property developer, sources said.

A state-engineered rescue of Country Garden by Ping An would be one of the most significant interventions to date by authorities to support the cash-squeezed and highly indebted property sector, which accounts for one-quarter of China's economic activity and has sparked fears of a broader financial crisis.

The following is a timeline of key measures authorities have taken this year.

Nov. 8 - Central bank Governor Pan Gongsheng said he would encourage financial institutions to keep bond and credit financing channels open to help address real estate sector weakness.

Nov. 7 - Shenzhen's state asset regulator and state-owned Shenzhen Metro pledged support for China Vanke with Shenzhen Metro saying it has prepared more than 10 billion yuan ($1.4 billion) worth of "market tools" to help with cashflow. Both are key shareholders in the developer.

Oct. 31 - China vowed to satisfy all reasonable financing needs of developers, regardless of whether they are private or state-owned firms. The statement was made at the Central Financial Work Conference, a twice-a-decade policy meeting.

Sept. 14 - China's central bank said it would cut the amount of cash that banks must hold as reserves for the second time this year to boost liquidity.

Sept 1. - China is set to take further action, sources said. Proposed measures include lifting home-purchasing curbs in non-core districts of major cities such as Beijing, Shanghai and Shenzhen and gradually removing price caps on new homes, they said.

Aug. 31 - China's central bank and financial regulator ease some borrowing rules for homebuyers, including lowering existing mortgage rates for first-home buyers and the down payment ratio in some cities.

Aug. 30-Sept. 1 - Major Chinese cities say they will allow people to take preferential loans for first-home purchases regardless of their credit record.

Aug. 25 - Local governments are permitted to scrap a mortgage rule so that people who have bought a home but then sold it having repaid their mortgage, can get preferential loans as first-time homebuyers, according to state media Xinhua.

Aug. 25 - China's cabinet approved guidelines for the planning and construction of affordable housing.

Aug. 21 - China cut its one-year benchmark lending rate.

July 24 - China's top leaders held a Politburo meeting and omitted the phrase "housing for living, not for speculation" in the official readout.

July 21 - The cabinet approved guidelines on transforming "urban villages" or underdeveloped areas in megacities, which will help underpin property investment.

July 10 - China's central bank extended until the end of 2024 some policies in a November rescue package to shore up the real estate sector.

June 20- China's central bank cut its key lending benchmarks, or loan prime rates (LPRs), for the first time in 10 months.

(Reporting by Liangping Gao and Ryan Woo in Beijing, Clare Jim in Hong Kong; Editing by Anne Marie Roantree and Edwina Gibbs)