$re = '/(?<=START)(?s)(.*?)(?=Closing)/';
$str = 'more useless gibberish at the begininng...
separated by new lines...
START Fund Class Fund Number Fund Currency
XYZ XYZ XYZ USD
bunch of text with lots of newlines in between... Closing 11.11 1,111.11 111,111.11
more useless gibberish between the groups...
separated by new lines...
START Fund Class Fund Number Fund Currency
XYZ XYZ XYZ USD
The word START appears in the middle sometimes multiple times, but it\'s fine bunch of text with lots of newlines in between... Closing 22.22 2,222.22 222,222.22
more useless gibberish at the end...
separated by new lines...';
preg_match_all($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