BERLIN, Dec 8 (Reuters) - Social Democrat Olaf Scholz became Germany's chancellor on Wednesday, ending 16 years of conservative rule under Angela Merkel and launching his three-way coalition that has pledged to boost green investment and strengthen European integration.

Scholz, 63, who over the past four years served as vice chancellor and finance minister in coalition with Merkel, won a majority of 395 votes from lawmakers in the lower house of parliament, Bundestag President Baerbel Bas said.

After being formally nominated by President Frank-Walter Steinmeier in the nearby Bellevue Palace, Scholz returned to the historic Reichstag building in the heart of the German capital to take the oath of office in front of lawmakers and become Germany's ninth chancellor since the end of World War Two.

Newly elected German Chancellor Olaf Scholz is sworn-in by Parliament President Baerbel Bas during a session of the German lower house of parliament Bundestag, in Berlin, Germany, December 8, 2021.

In a short speech, Scholz hailed Merkel as a great chancellor and thanked her for a close and trustful relationship over the past years.