March 27 (SeeNews) - Serbian oil and gas company NIS [BEL:NIIS], 56.15%-owned by Gazprom Neft, will invest more than 3.0 billion euro ($3.9 billion) in the modernisation and expansion of its business over the medium term, Belgrade-based newspaper Blic (www.blic.rs) reported on Wednesday, quoting Gazprom deputy board chairman Alexey Miller.