More Americans signed contracts to purchase homes in May, as pending sales climbed to their highest level in more than nine years.

The National Association of Realtors said Monday that its seasonally adjusted pending home sales index rose 0.9 percent to 112.6 last month. The index has increased 10.4 percent over the past 12 months, putting it just below the April 2006 level—which was more than a year before the housing bust triggered the Great Recession.