Fiat Chrysler (FCA) and Tesla have drawn up a plan to avoid the former having to pay fines for violating EU emissions rules, ONA reports citing the FT.
The paper says that under the deal the cars of electric automaker Tesla will be counted as part of the FCA fleet.
It will let the Italian carmaker offset carbon dioxide emissions from its cars against Tesla's, by bringing down its average figure to a permissible level.
FCA said it would "optimise the options for compliance the regulations offer".
The carmaker continued: "FCA is committed to reducing the emissions of all our products... the purchase pool provides flexibility to deliver products our customers are willing to buy while managing compliance with the lowest cost approach."
There is no indication of the specific amount that FCA has agreed to pay Tesla.
Last year FCA, which has been lagging behind rivals in the manufacture of electric vehicles, said it planned to spend €9bn (£7.75bn; $10.1bn) over four years to develop electric cars which complied with global emissions standards.
Under EU rules, carmakers can join with rival companies to form so-called open pools but none have done so until now.
FCA applied to form an emissions pool with Tesla, and also Alfa Romeo, in February.
Toyota and Mazda have also applied to the EU to form an emissions pool, as have Citroen, Peugeot, and Opel.