Apache

<IfModule mod_rewrite.c>RewriteEngine on
RewriteCond %{REQUEST_FILENAME} !-d 
RewriteCond %{REQUEST_FILENAME} !-f 
RewriteRule ^(.*?)([^/]*)$ $1index.php?$2[QSA,PT,L]</IfModule>

Nginx

location ~* \.(htm)$ {
        rewrite "^(.*)/(.+?).htm(.*?)$" $1/index.php?$2.htm$3 last;
    }