Oil Search Ltd., Papua New Guinea's biggest oil producer, expects to reach agreements with the government and partners by the year-end allowing a decision to start designing a $10b liquefied natural gas project. The economic viability of the Exxon Mobil Corp.-led LNG project has been ``fully tested'' and talks are underway with the government on fiscal terms, Port Moresby-based Oil Search said in a presentation lodged with the Australian Stock Exchange, according to a Bloomberg report. Oil Search may own between 28 percent and 32 percent of the venture, once the state and landowners take up stakes. The group is studying tapping gas from the Hides…