BRUSSELS (Reuters) - EU antitrust regulators have halted their scrutiny of the $130 billion merger of Dow Chemical <DOW.N> and DuPont <DD.N> after the companies failed to provide crucial data, the European Commission said on Friday.

The EU competition enforcer halted its investigation on Oct. 13, according to a filing on its website, the second time it has done so.

"This procedure in merger investigations is activated if the parties do not provide an important piece of information that the Commission has requested from them," Commission spokesman Ricardo Cardoso said in an email.

The companies are working constructively with the Commission and other regulatory authorities and still expect to close the deal in the first quarter of 2017, Dow Chemical spokeswoman Rachelle Schikorra said in an email.

The merger to create the world's largest crop protection and seeds company has triggered regulatory concerns that it may reduce competition in these areas as well as certain petrochemicals.

(Reporting by Foo Yun Chee; Editing by Keith Weir)