BRUSSELS, March 18 (Reuters) - Suez has lodged an appeal with Europe's second-top court after EU antitrust regulators rebuffed its bid to declare illegal Veolia's purchase of a further 29.9% stake in the French water and waste management company.

Suez filed its appeal at the Luxembourg-based General Court on Feb. 25, according to a filing on the court website.

"Suez respectfully disagreed with the European Commission's decision and seeks to annul the decision," a person familiar with the matter said.

It is likely to take months before the General Court holds a hearing and issues a judgment. The EU competition enforcer had dismissed Suez's arguments in a Dec. 17, 2020 finding.

Veolia already owns 29.9% of Suez and is seeking to acquire the entire company. It is in informal discussions with the EU regulator before formally requesting approval for its bid, which Suez has rejected on the grounds that the merger of two of the largest players in the sector would significantly reduce competition and hold back innovation. (Reporting by Foo Yun Chee; Editing by Susan Fenton)