Watchdog groups are sounding the alarm after two of the oldest and largest corporations in the United States—DuPont and Dow Chemical—announced Friday plans to merge into a $130 billion giant, thereby establishing the world’s biggest seed and pesticide conglomerate.

The new behemoth, named DowDuPont, would then be split into “three independent, publicly traded companies through tax-free spin-offs,” according to a joint corporate statement marking one of the the largest deals of 2015.