Oil tanker service provider Khunnathee Co has offered to pay up to 800 million baht for a 30% stake in Thai Maritime Navigation Co (TMN) Ð a state enterprise under the Transport Ministry, the Bangkok Post reported. (US$1=39 baht).   Khunnathee director Somboon Simasaengyaporn said his company planned to inject 700 million to 800 million…