$re = '/(?:EUR|USD|GBP)(\ )(?:(?:(?:\d+(\ ))+\d+)|\d+\.\d+|\d+)+(?:(\ )(?:Mio\.|million|billion))?/m';
$str = 'EUR 1.2
EUR 1.23
EUR 12
EUR 123
EUR 12 Mio.
EUR 12 345 Mio.
GBP 1 123 456 789 Mio.
USD 12 million
EUR 1.23 billion';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php