DETROIT -- General Motors has raised its cash incentives to consumers on many of its mid-sized and full-sized SUVs by $500 to $4,000, Reuters reported Friday. The automaker has also given its dealers incentives to sell more pickup trucks and SUVs, which have been slow sellers in recent weeks due to rising gasoline prices, the war in Iraq and the slow growth of new jobs, dealers said. GM has stepped up its incentives this month after sales in April were weaker than many Wall Street analysts had expected. The higher cash rebates involve some of GM's most popular SUVs, including the Chevrolet TrailBlazer, Chevrolet Suburban, GMC Yukon and GMC Yukon XL.GM said this week that it will halt production at its Oklahoma City plant, where it builds mid-sized SUVs including the TrailBlazer, the longer TrailBlazer EXT, the GMC Envoy XUV and Envoy XL. But otherwise, the automaker's truck plants continue to build more SUVs and pickups.GM must cut its high inventories of unsold SUVs and pickups, which are running far above typical levels for this time of year, or it could be forced to cut production, which would hurt earnings, George Magliano, director of automotive industry research at Global Insight, told Reuters.