A study of emerging market companies has indicated that nearly nine out of ten firms now offer at least some sustainability disclosure.

The report, released by the Social Investment Research Analyst Network, looked at firms in Brazil, China, India, Russia, South Africa, South Korea and Taiwan.

The study examined disclosure in five key areas - public disclosure of sustainability issues; a dedicated sustainability area within the website or annual report; existence of a stand-alone sustainability report; reference to the Global Reporting Initiative; and the existence of sustainability goals and benchmarks.

It concluded that among the seven countries, South Africa emerged as the overall leader in sustainability reporting, with six companies meeting all five criteria, accounting for 75 per cent of the country sample.

China was the laggard on sustainability reporting with three companies meeting none of the five criteria, and only 25 per cent of Chinese companies surveyed meeting all.

Sustainability reporting is designed to provide information on a company's environmental, social, and governance performance and assesses how they intend to improve their performance in these areas.

SIRAN representative Paul Hilton said: "We are encouraged that companies in emerging markets are getting the message. Analysts need information about environmental, social, and governance performance in order to identify the best companies in which to invest. Companies that are transparent will be rewarded by the market."

However, Noel Friedman, managing director of Research Products, remained cautious.

He said: "It is important to emphasise that a company can produce a high quality sustainability report and still fail to achieve sustainability in the areas relevant to its sector, such as climate change for utilities or human rights and the environment for mining companies."