METROMEDIA INTERNATIONAL Telecommunications said Wednesday it will merge with Actava Group Inc., Orion Pictures Corp. and MCEG Sterling Inc. to form a $1 billion international multimedia company. Billionaire John Kluge, chairman of Metromedia, a diversified communications company, will be chairman of the merged company, which will be known as Metromedia International Group Inc., the companies said. The newly formed company will marry Metromedia’s telecommunications and media businesses with the film businesses of Orion and MCEG Sterling, which have combined film libraries of more than 1,250 titles.