in SSI the includes command runs the cgi and returns the output to the browser, but in PHP the includes() function loads a file as text and looks for PHP/HTML code to run/output.
verify your path to the cgi program is correct, you may need to specify the complete path for the program to run.
the easy way here is to use the passthru command or the backtick operators. for example:
<?
$cgi_output = cgi-bin/news.cgi;
echo $cgi_output;
?>
http://www.php.net/manual/en/language.operators.execution.php
or
<? echo passthru('cgi-bin/news.cgi'); ?>
http://www.php.net/manual/en/function.passthru.php