Nov 17 (Reuters) - Centrica Plc CNA.L
* Centrica Norway's senior vice president Dag Omre said the firm plans to sanction its Oda field in the North Sea, formerly known as Butch, before the end of this year
* "We hope to be able to submit a plan of development to the ministry some time in December of this year," Omre told an industry conference in Stavanger on Thursday
* The cost estimate is now 5.5 billion NOK ($648.39 million) which is a 47 percent reduction compared to the initial estimate
* Will be developed as a subsea tie-back to the Ula platform
* Peak production of 35,000 boepd with expected production startup mid-2019
* Partners in the field are Suncor Energy SU.TO , Tullow Oil TLW.L , Faroe Petroleum FPM.L
* Centrica's Fogelberg discovery could come on stream by 2020/2021 if "it's robust enough," Omre said
* The firm is currently evaluating the Valemon and Noekken discoveries located in the Kvitebjoern area and sees potential production start post-2020/2021 Further company coverage: CNA.L ($1 = 8.4825 Norwegian crowns)