Mexico's largest cement firm CEMEX, a leading cement producer in the world, pledged to cut carbon dioxide emissions per ton of product 25 percent of 1990 levels by 2015, a statement released on Wednesday said.

"We acknowledge the global challenges posed by climate change and are committed to applying our ideas, our skills, our technologies, and our determination to engage in developing a pathway to a low-carbon economy," said Lorenzo Zambrano, CEMEX Chairman and CEO, quoted by the statement published on the company's website.

According to the statement, the company is reducing the energy needed to make cement by using a smaller percentage of the energy intensive ingredient clinker in its end product and substituting clinker with alternative materials such as fly ash from coal-fired power stations and blast furnace slag from the steel industry.

Besides, CEMEX said it had made efforts to increase its use of alternative fuels and renewable sources of energy as well as developing carbon capture and storage technologies.

The firm said it had also signed the Copenhagen Communique which calls for a worldwide commitment to cutting greenhouse gas emissions by 50 percent from 1990 levels by 2050.

The communique, signed by over 500 top international companies, is a statement from the international business community ahead of the ongoing United Nations climate change conference in Copenhagen.