SHANGHAI/HONG KONG (Reuters) -China announced plans on Thursday to channel hundreds of billions of yuan annually into shares from state-owned insurers, in the government's latest effort to support equity markets.

Authorities will in the first half of this year call on insurers to invest at least 100 billion yuan ($13.75 billion) of long-term funds into stocks, China Securities Regulatory Commission head Wu Qing said at a press conference.

The regulators will encourage big state insurers to invest 30% of new annual premiums in A-shares, and encourage mutual funds to increase their A-share holdings' tradable market value by at least 10% annually over the next three years, Wu said.

"Medium- and long-term funds play a crucial role in the capital market as professional investors. They act as the 'ballast' and 'stabilizer' to ensure the market runs smoothly and remains healthy," he said.

These measures will channel "several hundred billion" into onshore stocks every year, and consolidate the positive trend of the capital market, he added.

The plan also involves guiding mutual fund managers to increase investments in their own equity products, cut fund sales fees and promote the development of exchange-traded fund products.

The CSI300 blue-chip index advanced 0.6% while the Shanghai Composite Index jumped 1% by midday break. Hong Kong's Hang Seng Index added 0.2%.

A gauge tracking insurers jumped 2.6% in morning trade, with China Life Insurance rallying 4.3%.

Beijing has been intensifying policy support to prop up the stock market, which is weighed down heavily by a long-running property crisis, deflationary pressure and geopolitical tension.

Six Chinese government agencies, including the central bank and the securities regulator, released on Wednesday a slew of measures to guide medium- and long-term funds into the capital market.

Authorities have also introduced swap and re-lending schemes totalling 800 billion yuan for stock purchases in September as well as guidelines on market capitalisation management to encourage companies to improve shareholder returns.

The latest plan announced Thursday mirrors previous calls to promote capital markets, said Ben Bennett, Asia-Pacific investment strategist at Legal And General Investment Management.

"It's not a big surprise, but nice to see some tangible policies. These things need to go hand in hand with stronger growth and earnings expectations to be fully effective."

Stock prices have been highly volatile since authorities signalled support. The benchmark stock index CSI 300 surged 35% in the two weeks after that first stimulus announcement but disappointment with the degree and pace of implementation has seen the CSI 300 index halve that gain since.

($1 = 7.2728 Chinese yuan)