LONDON (Reuters) - Bosses from more than forty global companies called on negotiators to agree a United Nations climate change deal in Paris in December and pledged to make their own emission cuts, they said in an open letter published on Thursday.

The group of 43 chief executives, representing firms which generated a combined $1.2 trillion in 2014, said they would set internal emission reduction targets and called on negotiators to make sure a new international climate deal limits the global rise in temperatures to below 2 degrees Celsius.

The letter is designed to put pressure on government officials ahead of a spring meeting of a World Bank group in Washington from April 17-19.

Companies signing the letter include cement maker Lafarge, telecom group Erikson, consumer goods company Unilever, and car maker Volvo [VOLVO.UL].

“This initiative being launched today is a significant commitment in efforts to combat climate change. As businesses, we have the obligation to contribute to sustainable development,” Ignacio Galan, CEO of utility Iberdrola said in a statement.

Most governments missed an informal March 31 deadline to submit their climate pledges for the new deal.

Just Switzerland, Norway, Mexico, Russia, Gabon and the European Union had posted submissions U.N.’s submission website as of April 16.

The firms also join more than 340 institutional investors that last September called on governments to set carbon pricing policies that encourage the private sector to invest in cleaner technologies.