BEIJING (Reuters) -China's securities regulator promised to deepen reforms in its capital markets and open them up further in the second half of this year, as part of moves to implement policy support pledged by top leaders of the country.

The Politburo, a top decision-making body of the ruling Communist Party, promised on Monday to step up policy support for the economy amid a tortuous post-COVID recovery. The pledge lifted China's stock benchmark on Tuesday by the biggest daily gain since last November.

The China Securities Regulatory Commission (CSRC) said in a statement late on Tuesday it will promote the healthy development of 'platform' companies and maintain stable financing channels for real estate firms in capital markets.

The regulator also said that, in its mid-year work meeting, it decided to maintain stability in the operation of capital markets and in the balance between the primary and secondary markets.

(Reporting by Twinnie Siu in Hong Kong and Ethan Wang in Beijing, Jason Xue in Shanghai; Editing by Susan Fenton and Muralikumar Anantharaman)