Severance of shares: validity of US clauses?

Mr. C and Mr. J were partners of 60% and 40% of Tbt49, respectively, and had entered into a partnership agreement comprising an alternative offer clause or "American clause" according to which "in the event of a serious and persistent disagreement likely to lead to paralysis in the operation of the company and to prejudice the social interest, each partner could propose to the other to transfer to it all of its participation at a price and condi…