Computer giant Hewlett-Packard has placed two buildings at its Roseville campus on the market – a large office building and a major research facility. The 312,000-square-foot office building, which has been vacant for three years, accounts for more than 10 percent of the high-end office space in Roseville. The company also has received s approval to subdivide 116 acres into four parcels on the campus. The asking price for the properties has not been determined. H-P executives say the decision to sell the buildings and land is part of an ongoing effort to look at its real estate portfolio – and not a sign that the tech giant wants to leave the region. The company has about 3,800 employees in Roseville.