Dow Chemical Co.’s chief executive officer said the $59 billion merger with DuPont Co. may be delayed until February from a planned closing late this year, as European antitrust officials take more time to consider potential competition issues in pesticides and crop seeds.

Regulators’ “greatest concern is agriculture,” Dow’s Andrew Liveris said Monday in an interview with Bloomberg Editor-in-Chief John Micklethwait in New York. “One of the strongest lobbies in the world out there is the farm lobby, and in Europe, the agricultural sector is very, very critical to them, somewhat protected.”