PARIS, Sept 19 (Reuters) - Shares in TF1 and M6 fell on Monday after the French TV companies abandoned their merger plan, saying that antitrust requests had made the deal irrelevant.

TF1 shares were down 2.3 percent while M6 slumped down by 6.3 percent in early session trading.

Under the initial merger plan, French conglomerate Bouygues would have ended up controlling the merged group with a 30% stake while M6's parent, German media group Bertelsmann , would be the second biggest shareholder with 16%.

The companies have been facing stiff opposition in recent months, from the likes of media group Vivendi, which owns France's biggest pay-TV group Canal Plus, as well as from Xavier Niel, the founder of telecoms and media group Iliad. (Reporting by Tassilo Hummel; Editing by Sudip Kar-Gupta)