subsidiary, and on 28 March 1991, another step to the expansion of the group's activities was made through the signing of a joint-venture partnership agreement with Škoda automobilová a.s. of Czechoslovakia, accompanied with the acquisition of a 30% stake in the Czech car manufacturer on 16 April 1991. On 19 December 1994, the group began the acquisition of Škoda Auto by raising its share to 60.3%. Later, on 11 December 1995, it became the Czech company's largest and controlling shareholder by increasing its share up to 70%. Three prestige automotive marques were added to the Volkswagen portfolio in 1998: Bentley, Lamborghini, and Bugatti. 2000 to present On 30 May 2000, after having gradually raised its equity share, Volkswagen AG took over the full ownership of Škoda Auto, making the company a wholly owned subsidiary. From 2002 up to 2007, the Volkswagen Group's automotive division was restructured so that two major Brand Groups with different profile would be formed, the Audi Brand Group focused on more sporty values – consisted of Audi, SEAT and Lamborghini – and the Volkswagen Brand Group on the field of classic values – consisted of Volkswagen, Skoda, Bentley and Bugatti – with each Brand Group's product vehicles and performance being respectively under the higher responsibility of Audi and Volkswagen brands. Volkswagen Group revealed on 24 October 2009 that it had made an offer to acquire long-time partner and German niche automotive manufacturer Wilhelm Karmann GmbH out of bankruptcy protection. In November 2009, the supervisory board of Volkswagen AG approved the acquisition of assets of Karmann, and planned to restart vehicle production at their Osnabrück plant in 2012. In December 2009, Volkswagen AG bought a 49.9% stake in Dr. Ing. h.c. F. Porsche AG (more commonly known as Porsche AG) in a first step towards an 'integrated automotive group' with Porsche. The merger of Volkswagen AG and Porsche SE was scheduled to take place during the course of 2011. On 8 September 2011, it was announced that the planned merger "cannot be implemented within the time frame provided for in the Comprehensive Agreement". As reasons, unquantifiable legal risks, including a criminal probe into the holding's former management team were given. Both parties "remain committed to the goal of creating an integrated automotive group with Porsche and are convinced that this will take place". On 4 July 2012 Volkswagen group announced they would wrap up the remaining half