Greece only discusses giving cash collateral to Finland in return for its participation in the country's second bailout, Finance Minister Evangelos Venizelos said on Wednesday.    "We are only talking about cash guarantees which do not create any problem to Greece's stabilisation plan," Venizelos Real FM Radio in an interview.    Finland has proposed that Greek state assets be transferred to a Luxembourg-based holding company and held there as security for new loans to Athens, according to an internal document seen by Reuters.