The next few years present an excellent opportunity for investing in firms that develop or sell airport-security equipment, according to a new market analysis by the consulting firm Frost and Sullivan.

For one thing, the airport security market is giving all indications it will start another boom period, following an initial rush of federal spending that came on the heels on the 9/11 terrorist attacks. In 2003, Transportation Security Administration (TSA) purchases from security firms spiked at nearly $6.5 billion. That created a temporary "overcapacity" of equipment, according to Rani Cleetez, a Frost financial research analyst.

In the following year, 2004, aviation-security spending from TSA dropped to about $2 billion. Recently, there has been an annual 20 percent increase in spending that Frost expects will continue into 2007 and 2008. This translates into another spike.

In fact, the top 30 firms in the field, which earned a collective $2.6 billion in 2004, are expected to bring in more than $6.1 billion in 2009. The global aviation services market is now worth $69 billion, with 75 percent of that represented by airport security equipment. North America and Europe account for 40 percent and 35 percent of that smaller market segment of security equipment.

Furthermore, the "market mix" in both North America and around the globe is not expected to change significantly over the next few years, says Ken Herbert, Frost's global vice president, and co-author of the analysis with Cleetez. "Market mix" refers to the regulatory, political and economic conditions that can confound predictions for the growth rate in particular industries or market segments.

Frost was founded in 1961 with a mission of "providing market consulting on emerging high-technology and industrial markets

Within the airport-security equipment industry, the firm expects to see particularly healthy growth rates in an unusually high number of industry sub- segments, which are rank ordered in the box at right. But Cleetez cautions against taking this ranking too literally, as there is actually not that much separation between these sub-segments. For example, the top-rated area, digital surveillance, is given a 22.4 percent projected growth rate and the second-place area, explosive detection, will be at 21.9 percent. (The firm does not want to disclose the exact growth rates in the other areas.)