Redirecting Visitors Based on Country Location in Apache2
This can be done easy in Apache2 by installing the Mod_geoip2 Apache Module, basically it connects to various API based GEO database providers and detect where the visitor is located, you can then use this collected data to redirect. A simple example of the .htaccess file would look like:
GeoIPEnable On
GeoIPDBFile /path/to/GeoIP.dat
# Redirect EU
RewriteEngine on
RewriteCond %{ENV:GEOIP_COUNTRY_CODE} ^EU$
RewriteRule ^(.*)$ http://www.EU-Site.com$1 [R,L]
# Redirect Asia, North America and South America
RewriteEngine on
RewriteCond %{ENV:GEOIP_COUNTRY_CODE} ^(NA|SA|AP)$
RewriteRule ^(.*)$ http://www.US-Site.com$1 [R,L]
As you can see this is a fairly easy task but your need to pay for up to date DATABASES and normally these are charged per X amount of requests. For the module it can be found here: mod_geoip2