PITTSBURGH (AP) — The wheeling and dealing over the natural gas-rich Marcellus Shale has hit the pause button.

Marcellus mergers and acquisition activity fell to zero in the third quarter of 2012, after major energy companies spent tens of billions of dollars over the last three years, according to a quarterly report Thursday of the financial firm PricewaterhouseCoopers. In the previous quarter, the deals totaled $1.6 billion.