Swiss investment vehicle Klesch Group is considering snapping up insolvent refiner Petroplus' Coryton plant in Britain as well as the Ingolstatt site in Germany, chief executive Gary Klesch said in an interview on Wednesday.

Klesch told French oil newsletter Bulletin de l'Information Petroliere that his group was not interested in the Petroplus refinery based in Cressier, Switzerland, because the plant was too small.

Klesch, who first said in January he was considering acquiring the Swiss refiner's Petit Couronne site in France, reiterated that interest in the interview but described it as a situation of now or never.

He declined to quantify the investments needed at the refinery, however.

We know what must be done at the Petit-Couronne refinery, he was quoted as saying. We are ready to take over the refinery. And ready to invest the necessary money in Petroplus but not to take responsibility for others' errors.

Petroplus' assets became acquisition targets when the company was forced to close three of its plants, including Petit Couronne in France, after lenders froze credit lines late in December.

(Reporting by Elena Berton; Editing by Christian Plumb and Helen Massy-Beresford)