The founder of activist investment company Amber Capital, which lost out this week in a bid to shake up the governance at French group Lagardere, said on Wednesday he had no plans to exit his stake in Lagardere and added that he could even raise it.

"We have no plans to sell our stake, and we are not excluding increasing it," Amber Capital founder Joseph Oughourlian told BFM Business TV.

Amber Capital has raised its stake in Lagardere to 18% in recent weeks, making it the media and publishing conglomerate's top shareholder ahead of the Qatari Investment Authority.

Lagardere shares rose 1.6% in early session trading.

On Tuesday, Lagardere managed to fend off Amber's most daring attempt yet to shake up governance at the company, after shareholders rejected the activist investor's call to replace the supervisory board.

Lagardere, locked in a stand-off with Amber over the past four years, had strengthened its defences with the arrival of new allies and investors, including French media magnate Vincent Bollore and his Vivendi group.

Amber Capital's Oughourlian told BFM Business that he had not had any contact with Bollore, but described Bollore as a "good travelling companion."

(Reporting by Sudip Kar-Gupta, editing by Louise Heavens)