LOS ANGELES (Reuter) - California, which last month said it would probably drop its controversial rule requiring large numbers of electric cars to sold starting in 1998, Thursday unveiled an alternative proposal for phasing in the vehicles that would delay the mandate by five years.

The California Air Resources Board (CARB) said the new proposal would suspend the rules until the year 2003, but would ask that car makers in the meantime work to develop electric cars.

It also said it would put in place different emissions regulations to keep the state, which suffers some of the worst air pollution in the nation, on track in its efforts to come into compliance with the U.S. Clean Air Act.

The zero emission vehicle rule requiring that 2 percent of the cars offered for sale by major automakers be electric vehicles by 1998, has been considered a cornerstone of California's pollution reduction efforts since it was drafted in 1990.

But regulators recently lost their resolve on the matter, after car makers and other scientific exerts advised them that battery technology was not advanced enough to make an electric car that consumers would want to buy.

The electric cars now being made usually can drive no more than 100 miles on a single charge, and much less in inclement weather or on hilly terrain. They also take hours to recharge.

Under the alternative proposal unveiled Thursday, car makers would voluntarily manufacture electric cars in volumes totaling 5,000 in 1996 and 1997 and 14,000 in 1998. The 2 percent 1998 rule would have required about 22,000 electric cars sold that year.