<?php
$string = '
<table border="1" cellspacing="0" cellpadding="0" style="table-layout:fixed;font-size:13px;font-family:arial,sans,sans-serif;border-collapse:collapse;border:1px solid #ccc" dir="ltr">
<colgroup>
<col width="54">
<col width="337">
<col width="233">
<col width="96">
<col width="98">
<col width="86">
</colgroup>
<tbody>
<tr style="height:18px;">
<td style="padding:0px 3px 0px 3px;vertical-align:bottom;background-color:#fff2cc;text-align:center;vertical-align:middle;border-right:;border-bottom:;">128882</td>
<td style="padding:0px 3px 0px 3px;vertical-align:bottom;background-color:#fff2cc;text-align:center;vertical-align:middle;border-right:;border-bottom:;direction:ltr;color:#000000;">экономика (10-15 стр) </td>
<td rowspan="1" colspan="1" style="padding:0px 3px 0px 3px;vertical-align:bottom;background-color:#fff2cc;text-align:center;vertical-align:middle;border-right:;border-bottom:;direction:ltr;color:#000000;">
<span>
<div style="max-height:35px">Анна http://content-available-to-author-only.com/s aaa@mail.ru 2? +7(111) 111-11-11 3? --- </div>
</span>
</td>
<td style="padding:0px 3px 0px 3px;vertical-align:bottom;background-color:#fff2cc;text-align:center;vertical-align:middle;border-right:;border-bottom:;direction:ltr;color:#000000;" rowspan="2">неделя </td>
<td style="padding:0px 3px 0px 3px;vertical-align:bottom;background-color:#fff2cc;text-align:center;vertical-align:middle;border-right:;border-bottom:;">750</td>
<td colspan="1" rowspan="3" style="padding:0px 3px 0px 3px;vertical-align:bottom;background-color:#fff2cc;text-align:center;vertical-align:middle;border-right:;border-bottom:;direction:ltr;color:#000000;">
<span>
<i style="max-height:35px">/к</i>
</span>
</td>
</tr>
<tr style="height:18px;">
</tbody>
</table>
';
$pattern = '/<([a-z][a-z0-9]*)++(?:( rowspan="\d+")|(?:[^>]?(?=( rowspan="\d+")?))++)[^>]*?(\/?)>/i';
echo $result;
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