October goes into the record books as a month of mega merger mania. It was a record month for making deals, with $489 billion in mergers and acquisitions. That's the highest amount in at least 12 years, according to data compiled by Bloomberg. The biggest deal of the year was announced late in the month, when AT&T's ( T) $85.4 billion bid for Time Warner ( TWX). Bloomberg reports that so far this year, there have been 32 deals valued at more than $10 billion. The bid deal announced on the final day of the month was CenturyLink's ( CTL) $34 billion acquisition of Level 3 Communications ( LVLT) .