DETROIT -- More than 100,000 tons of flat-rolled steel will be required annually for the body, closure and frame applications in two new crossover vehicles that General Motors Corp. plans to add to its Hummer vehicle line before the middle of this decade.

One, known as the Hummer H3, will be built on a forthcoming new GM pick-up-truck platform at its facilities in Shreveport, La., the other will be a pick-up version of GM's Hummer H2 sport utility vehicle (SUV) which will be produced for GM by AM General Corp. in Mishawaka, Ind.

The Hummer H3 will bean intermediate-size, SUV-like vehicle--the smallest model in GM's Hummer family of multi-terrain vehicles--that will, be built in annual volumes, of up to 100,000 units. The platform for the H3s will be the same as that used in the new Chevrolet Colorado pickup trucks that will precede the H3s into the market next year.

According to GM sources at the 2002 Society of Automotive Engineers' Congress and Exhibition here, the Hummer H2 sport utility trucks, with cargo boxes in the rear, will be built in only a fraction of the volumes of the H3s. The H2 SUVs are going to be introduced this year as 2003 models while the pickup versions are expected to be introduced in 2004, although this could change.

GM is tooling a new plant in Louisiana next to an existing facility currently used to assemble compact-size Chevrolet S-10 and GMC Sonoma pickups, which will be phased out of production starting next year. Both plants will assemble the new Colorado pickups and the Hummer H3s, and new stamping and weld-assembly facilities there will be used to make the body and closure panels and subassemblies.

In Indiana, AM General has built a new plant to make the Hummer H2 SUVs and cargo-box-equipped sport utility trucks. Both the SUVs and trucks will be smaller than the Hummer H1, which AM General also builds for GM. Unlike the Hummer His, which have aluminum bodies on steel frames, the H2s and H3s will use steel in both bodies and frames.

GM sources said the H3s would require 90,000 tons of flat-rolled steel--galvanized, cold-rolled and hot-rolled--per year for their body, closure and frame components at full vehicle production rates of 100,000 units annually.