Last week's earthquake and tsunami in northern Japan and its aftermath in the form of nuclear reactor crisis present a near-term disruption for a handful of software companies that have exposure to the region.

Japan is the third-largest economy in the world and one of the largest trading partners of the U.S., so any long term disruption should ripple through the U.S. and the global economy.

We think the worst-case scenario at this point would be if Tokyo were to shut down because of dangerous radiation levels. This would have global repercussions and result in a slowdown of the global economy, FBR Capital Markets analyst David Hilal wrote in a note to clients.

Impact on Salesforce (NYSE: CRM)

The analyst said Asia-Pacific accounted for 14 percent of Salesforce.com's revenues in fiscal 2011 and was the company's fastest-growing region (54 percent growth in FY11).

Japan is the largest component of Salesforce.com's Asia-Pacific exposure.

Hilal estimates Japan accounts for approximately 8 percent to 9 percent of total revenues.

Saleforce.com has aggressive growth plans for Japan as evidenced by the company recent acquisition of the non-controlling interest in its Japanese subsidiary for $151 million and it is building a new data center in Japan.

These growth initiatives may now be muted/delayed due to the recent tragedy.

We note that the subscription nature of Salesforce.com's revenues means that near-term revenues should not be impacted; however, bookings may be if deals get pushed out, the analyst added.

Shares of Salesforce closed Tuesday's regular trading session at $125.55 on the NYSE.