WASHINGTON, June 4 (Reuters) - Colorado said on Tuesday it plans to move forward with plans to adopt California's zero emission vehicle mandate after talks with major automakers failed to reach a deal on voluntary efforts to boost electric vehicle sales.
The Alliance of Automobile Manufacturers, a trade group representing General Motors Co, Toyota Motor Corp , Volkswagen AG and others, in April met with Colorado Governor Jared Polis in a bid to convince him that voluntary efforts to boost electric vehicles make more sense.
Colorado state officials said in a statement that after talks over four weeks "we were unable to reach agreement on a voluntary approach that could be considered as a potential alternative to the zero emission vehicle (ZEV) standard."
A spokeswoman for the auto group said it planned to continue to work with the state.
"Unfortunately, while these discussions were encouraging, there were many complex details that we were unable to resolve," the spokeswoman said. "We remain committed to zero emission vehicles and to working with the Polis administration to accelerate the electric vehicle market in Colorado."
The state plans to finalize requirements that will take effect starting in the 2022 model year.
"We are optimistic that ongoing dialog with automakers through the rule-making process will make more electric vehicle models available to Coloradans as soon as next year," the state officials said.
Polis in January signed an executive order directing the state to adopt California's ZEV rules, joining nine other U.S. states including Maryland, Massachusetts, New Jersey, New York and Oregon.
The auto group said in an April 29 letter seen by Reuters that its members would agree to make all EVs available for sale in Colorado that are on sale in California by January 2020 and commit to additional marketing efforts for EVs.
The California ZEV mandate, first adopted in 1990 and revised on numerous occasions, requires an increasing number of electric vehicle or other zero emission vehicles.
Last year, California forecast that about 8 percent of the state's new vehicle sales in 2025 will be zero emission and plug-in electric hybrids.
In August, the Trump administration proposed freezing fuel efficiency standards at 2020 levels through 2026 and barring California from imposing its own vehicle emission rules or setting requirements for zero emission vehicle sales.
California and 18 other states, including Colorado, have said they will fight the Trump administration's freeze in court, a legal battle that could leave automakers in regulatory limbo for years. (Reporting by David Shepardson; Editing by Dan Grebler)