From the Thomson Reuters data team:

    Exxon Mobil’s $40.7 billion acquisition of XTO Energy ranks as the sixth biggest announced worldwide M&A transaction this year and the fourth biggest US target transaction. The deal ranks as the eighth biggest Energy & Power M&A transaction in history and marks the biggest US transaction since Chevron’s $43.3 billion acquisition of Texaco in October 2000.  The $85.1 billion combination of Exxon and Mobil in December 1998 ranks as the biggest Energy & Power deal on record. Worldwide, energy & power M&A totals $330.9 billion for year-to-date 2009, an 18.1% decrease from last year at this time.  Worldwide M&A in the oil & gas sector totals $203.7 billion, a 17.2% increase over last year at this time. In the US, energy & power M&A accounts for 12.2% of overall activity, a 7.5 decline from last year.  Oil & gas M&A activity in the US totals $74.9 billion, a 35.6% increase over 2008. With the announcement, JP Morgan (advisor to Exxon Mobil), moves from fourth place to third place for worldwide merger advisors, with $467.5 billion in announced deals from 299 deals. Barclays and Jefferies (advisors to XTO Energy) rank 10th and 21st, respectively. In the US, JP Morgan remains in third place with $269.5 billion.  Barclays moves to sixth place from seventh and Jefferies moves from 23rd place to 13th.