LONDON/SAO PAULO (Reuters) - More than 100 companies, including Unilever, L'Occitane and Iberdrola, have called on governments to enact tougher policies to reach a U.N. goal on halting nature loss by the end of the decade.

With more than 1 million species on the brink of extinction, the world agreed to a landmark deal in 2022 to protect biodiversity, including a pledge to protect 30% of the world's natural ecosystems.

Countries will convene at the COP16 biodiversity summit in October in Colombia to work out the details of implementing the pledge.

In a letter shared exclusively with Reuters ahead of the talks, 132 companies with combined revenues of $1.1 trillion demanded stronger action.

Other companies that signed the call for action - on measures ranging from subsidy reform to water use and farming practices - include miner Teck Resources, food group Danone, energy company RWE and cement maker Holcim.

Humans are decimating wildlife by destroying native ecosystems, polluting nature and driving climate change.

Whatever the financial cost of preventative measures, some of those backing the letter have said the much bigger cost would be from lost species as food production relies on dwindling numbers of pollinators, for instance, and disrupted water systems that depend on vulnerable ecosystems.

"If we don't focus on nature, if we don't focus on biodiversity, the business that we operate may not even exist in years to come," said Rishi Kalra, executive director and group chief financial officer of Olam Food Ingredients (ofi), one of the world's biggest suppliers of food and beverage ingredients.

For example, the company relies on bees to pollinate its almond farms, Kalra said in an interview.

"Food may not be available. People may not have a livelihood if nature is not protected."

Deforestation of the Amazon rainforest in Brazil, for example, has reduced rainfall and shifted weather patterns in critical farming areas that supply a major portion of the world's soybeans and beef.

"Without nature, without water, it's impossible to have human life, not even thriving, but just existing," Nestle Latin America CEO Laurent Freixe said.

Because nature-friendly strategies may increase costs in the shorter term, some companies have been reluctant to act unless governments set market-wide rules or offer the incentives needed to compel action.

Voluntary corporate action would not be enough alone, said the letter, coordinated by advocacy group Business For Nature, which has drawn up policy recommendations.

Governments, the letter said, needed to ensure businesses and financial actors protect and restore nature.

Further action must include ensuring sustainable resource use, valuing and embedding nature in decision-making and disclosure and stronger global agreements to address nature loss.