The Sacramento region’s third-largest homebuilding has merged its Sacramento and Bay Area divisions. KB Home now has one Northern California division based in Pleasanton. The company’s Sacramento office remains open to support several projects still selling in the region. The move makes KB Home the latest builder to slash staff and combine offices to deal with a sluggish housing market. Sacramento had 5,100 fewer construction-related jobs in July than a year ago, according to the state’s Employment Development Department. Los Angeles-based KB Home has been a large player in the Sacramento market. It sold 182 homes in the six-county region in the first six months of 2008. That’s about a 6.1 percent share of the market.