Allianz SE (AZ), Consolidated Edison Inc. (ED), Siemens AG (SI), BASF SE (BASFY), Boeing Co. (BA) and Cisco Systems Inc. (CSCO) are among the global corporations leading efforts to tackle climate change, as the issue moves to the forefront for the world's top companies, the Carbon Disclosure Project's 2009 report on the Global 500 said Monday.

This year, more of the world's largest 500 companies responded to the CDP survey than in the past. They also gave more detail on their activities to mitigate and adapt to climate change. The CDP has published its climate change report every year since 2003.

The increase in disclosure this year to 82% of the Global 500 from 77% last year shows that despite the economic downturn and other pressures, climate change remains high on the agenda and is becoming an increasingly important issue for the majority of large companies, CDP Chief Operating Officer Paul Simpson said.

"The increase is significant, and it really shows where the world has moved in the past five years," Simpson said in a telephone interview ahead of the report's release.

"When companies are responding voluntarily and in increasing numbers, it shows that at the very senior level in the company, climate change is seen to be a significant issue for their corporations and that they must respond, must demonstrate themselves to be a responsible company on this issue," Simpson said.

Attitudes of the Global 500, based on market capitalization in the FTSE Global Equity Index Series, are significant because they account for around 11.5% of total global emissions.

The report's release comes as business leaders, heads of state and the world's major investors congregate in New York this week for a climate change summit led by United Nations Secretary General Ban Ki-moon. The talks are to prepare for the U.N.-led climate change conference in Copenhagen in December to negotiate a successor treaty to the Kyoto Protocol.

The discussions in New York are to continue at the G20 meeting that follows in Pittsburgh, Pa., Sept. 24-25.

Companies responding to the CDP survey said a global, legally binding agreement in Copenhagen is important to provide the increased certainty they need to set medium- and long-term emissions reduction targets, the report said.

Bayer AG (BAY.XE), BASF, HSBC Holdings PLC (HBC), Wal-Mart Stores Inc. (WMT) and Chevron Corp. (CVX) topped the table on carbon disclosure this year, giving the most information about their efforts to tackle climate change.

In addition to providing better disclosure, the Global 500 also is performing better than last year with targets to reduce emissions, engaging with key policy makers and developing new products and services to adapt to the new business environment, the report showed.

This year, 51% of the Global 500 companies said they have targets to reduce emissions versus 41% last year and 36% have targets that go beyond 2012, when the current climate change treaty expires.

Chemicals company BASF SE, Cisco Systems Inc. and U.S. aerospace company Boeing Co., the three companies that are among both the top 10 disclosers and performers, also demonstrate the move now to take advantage of the opportunities rather than see climate change legislation as a risk, Simpson said.

Cisco Systems is developing very high quality video conference equipment for executives trying to reduce airline travel, and Boeing is seeking to develop more efficient airplanes that emit less carbon dioxide.

"Companies are starting to realize they can make a lot of money if they take advantage of the opportunities," Simpson said.

Companies are more willing to take action on emissions now that the U.S. is involved in the climate change debate, following the election of Barack Obama. Increasing evidence from the scientific community about climate change and the visible impact already being seen around the world is also spurring companies on, Simpson said.

Geographically, companies in Europe, where there already is a carbon cap and trade scheme, tended to achieve higher scores on both disclosure and performance.

However, more companies from the developing world, which will be key to securing a global agreement in Copenhagen, are now responding.

According to the report, 44% of the 36 Global 500 companies in developing countries Brazil, Russia, India and China responded this year, double last year's rate. A 100% response rate was received from Brazil.

CDP, a London-headquartered non-governmental organization, represents 475 institutional investors with $55 trillion in assets under management.

-By Selina Williams, Dow Jones Newswires +44 207 842 9262; selina.williams@dowjones.com