The study revealed that Morgan Stanley has advised on M&A deals worth $574.3 billion so far this year, compared with the Goldman's $535.8 billion.
JPMorgan remains in third place in the league table, more than $100 billion behind Goldman, despite its role in ExxonMobil's $40.4 billion takeover of XTO Energy.
Goldman is still the leading M&A advisor in the US, ahead of Morgan Stanley and JPMorgan. However, it is a different story in Europe, where Morgan Stanley is the market leader.
Mergermarket also noted that smaller advisory firms have enjoyed a successful 2009, with Evercore Partners, Rothschild and Barclays Capital all involved in some significant deals.
The findings of the report differ from a recent study published by Dealogic, which concluded that Goldman remains on course to retain its position as the world's leading M&A advisor.
Dealogic's figures suggested Goldman has worked on deals worth $616.9 billion during 2009, while Morgan Stanley's M&A deals totalled just $599.6 billion.
By Gary Cooper