STOCKHOLM, Nov 15 (Reuters) - Siem Industries and Topcon Corporation will launch an offer for Norwegian satellite positioning system firm Veripos, trumping a bid by Sweden's Hexagon, the two firms said on Friday. Industrial holding company Siem Industries SEMUF.PK , Veripos' largest shareholder, and Japanese positioning technology firm Topcon 7732.T said they would offer 30 Norwegian crowns ($4.85) in cash per Veripos VPOS.OL share. This would value Veripos, which makes positioning systems for offshore oil companies, at around 1 billion Norwegian crowns in total ($162 million). In October, measurement technology firm Hexagon made a 28 Norwegian crowns per share offer for Veripos. ID:nL6N0I408F Veripos shares, which have consistently traded above 28 crowns since October 14 when Hexagon launched its offer, were up 7.9 percent at 31.3 crowns at 0946 GMT. Veripos shares closed at 23 crowns the day before Hexagon's offer. Topcon and Siem said their offer would be unconditional, meaning they did not require a certain level of acceptance. "Veripos will continue to be managed as an independent entity for the benefit of all shareholders," Siem and Topcon said in a statement. Siem owned 21 percent of shares in Veripos as of September 30. ($1 = 6.1863 Norwegian krones) ($1 = 6.1863 Norwegian krones) (Reporting by Sven Nordenstam) ((sven.nordenstam@thomsonreuters.com)(+46)(0)(8 700 11 66)(Reuters Messaging: sven.nordenstam.reuters.com@reuters.net)) Keywords: VERIPOS BID