Ford's introduction of a petrol-electric hybrid sport utility vehicle is a good start, but will have little immediate impact on its dismal fuel economy record, US environmental groups reportedly said on Wednesday.

Reuters noted that the fuel-sipping version of Ford's compact Escape SUV goes into commercial production this week and environmental activists hailed it as a step in the right direction.

But they reportedly said Ford - which has a US car and truck fleet with the lowest average fuel economy among the top six automakers - would have to go much further to win recognition as a company truly committed to the environment.

"The hybrid Escape is a rolling advertisement for better technology and a cleaner environment," David Hamilton, director of the Sierra Club's Global Warming and Energy Programme, said in a statement cited by the news agency.

Like other environmentalists, he noted that Ford initially plans on building just 20,000 hybrid Escapes a year - a blip in Ford's total annual vehicle production, Reuters said.

"We look forward to helping build demand for these vehicles and encourage Ford to put this gas-saving technology to work on all their vehicles," Hamilton reportedly said.

According to Reuters, Ford sources have said the company will initially sell the hybrid Escape at a loss because of high development costs.

Ford spokeswoman Kristen Kinley told the news agency the automaker plans to introduce two other hybrid vehicles in the near future, however, and added that the company was "aggressively pursuing" better fuel economy.

Elisa Lynch of Bluewater Network, a group that works to cut dependence on fossil fuels, reportedly called Ford's hybrid Escape SUV "a brilliant advertisement for better technology," picking up on the same theme as the Sierra Club's Hamilton.

But selling just one limited-production model of hybrid "won't help the company escape the fact that they still have the worst fuel economy of any major automaker," she told Reuters.

"While Ford introduces its new hybrid, they continue to aggressively market a fleet of gas-guzzling cars and trucks," Lynch said, according to the report. "These vehicles could have dramatically improved fuel efficiency using even just off-the-shelf conventional technologies."

According to Reuters, Jennifer Krill of the Rainforest Action Network said: "We liken Ford's hybrid Escape release to an alcoholic going from 20 drinks a day to 19 drinks a day. Ford cannot Escape its oil dependence with a few thousand hybrid SUVs."