June 27 (Bloomberg) -- Ford Motor Co., under pressure to trim its reliance on trucks, said it's taking a measured approach on plug-in hybrid vehicles by letting rivals assume the risk of marketing the new technology.

``If customers aren't buying them, we're not making them,'' Ted Miller, Ford's senior manager of energy storage, said in an interview yesterday. ``If there's going to be a true plug-in hybrid market, we're going to be there. It's just that that's a huge commitment to actually go to production.''

That tack may force the world's third-largest automaker to play catch-up if plug-ins such as General Motors Corp.'s Chevrolet Volt concept can be built in high volume. The chief hurdle is a rechargeable battery for extended electric-only use.

GM and Toyota Motor Corp., the biggest automakers, are racing to introduce a vehicle able to recharge from household electrical sockets in 2010. Ford has a test fleet of 20 plug-in sport-utility vehicles, without a target date for selling them.

``It seems a good strategy because it's cheap, they don't have to take this risk,'' said Mike Omotoso, a powertrain analyst at market-research firm J.D. Power & Associates in Troy, Michigan. ``If Ford sees in a few years that the plug-ins are a commercial success, they can adopt the existing technology.''

Ford's 2008 U.S. sales fell 11 percent through May, paced by a 19 percent drop in F-Series pickups as gasoline neared $4 a gallon. Sliding truck demand contributed to $15.3 billion in losses at Dearborn, Michigan-based Ford in the past two years.

`Hail Mary'

Miller said an overly aggressive approach to introducing plug-ins is akin to a ``Hail Mary,'' using the U.S. sports metaphor for a desperation play.

``The Hail Mary means that we're probably going to have to neglect a lot of other things,'' he said.

Ford plans to introduce plug-in hybrids in low volumes in the U.S. between 2012 and 2020, spokesman Said Deep said in an interview, adding that he couldn't be more specific about the timetable.

``We are working on the technology,'' Deep said. ``But we have to determine: How well does this hold up in the real world?''

Operating a plug-in vehicle may be difficult for motorists in cities such as New York and San Francisco, Miller said. Manufacturers ``assume you have access to a plug, and that's simply not the case in many cities where people park on the street or just don't have a garage,'' he said.

`Bucket of Money'

``If we're spending significant resources on plug-in hybrids, it means we don't have a bucket of money'' to develop traditional hybrid vehicles, such as a gasoline-electric version of the Fusion sedan due later this year, Miller said. ``Spending significantly less on hybrids is probably not a good option.''

Ford teamed with Southern California Edison starting last year on battery research, and Executive Vice President Mark Fields urged the U.S. Congress this month to commit more money for plug-in vehicle development.

Ford slipped 9 cents to $4.98 at 4:01 p.m. in New York Stock Exchange composite trading, the lowest since the shares reached $4.94 on Oct. 31, 1985. Ford has lost 26 percent this year.

Miller said Ford is staking its near-term future on improving hybrid sales in the U.S., where it hasn't had an annual sales gain since 2000.

`Sit Back'

``Our position in the hybrid market makes it easier for us to sit back'' and evaluate the viability of plug-ins, he said. Miller wouldn't be specific about Ford's hybrid-development budget. The automaker spent $7.5 billion for research and development in 2007, according to data compiled by Bloomberg.

By year's end, Ford will add two more hybrid versions of existing sedans, the Mercury Milan and Ford Fusion, for a total of four models, Deep said.

Conventional hybrids such as Toyota's Prius use a nickel- metal hydride battery that's employed mostly at low speeds and to enhance the output of a small gasoline engine.

Plug-ins would tap lighter, stronger lithium-ion batteries and wouldn't need another power source on short trips. GM has promised a car that can travel at least 40 miles (64 kilometers) on battery power, then recharge at an outlet or via an onboard gasoline engine.

Still, lithium-ion batteries for plug-ins remain under development, and they may cost about $15,000 each, according to Paul Boskovitch, chief engineer for hybrid systems for auto- parts supplier Ricardo Inc. That compares with $3,000 to $6,000 for nickel-metal versions, Omotoso said.

Toyota, which developed the first commercially available hybrid and leads global sales of the technology, announced plans for a plug-in model in January.

GM and Ford are paring truck production this year to adjust to changing consumer sentiment away from pickups and SUVs in favor of smaller cars and wagons. U.S. auto sales may fall to 14.5 million units in 2008, which would be the lowest in 15 years, according to Deutsche Bank.

To contact the reporter on this story: Greg Bensinger in New York at gbensinger1@bloomberg.net

Last Updated: June 27, 2008 18:29 EDT