Exxon Mobil and a seismic research company it hired to search for oil off the coast of Guyana declined on Monday to say when they might resume exploration work halted after a weekend confrontation with Venezuela’s navy. The foreign ministries of both neighboring South American countries said the incident had occurred within their territorial waters. A century-long border dispute has heated up in recent years as Irving, Texas-based Exxon ( XOM.N ) has discovered more than 5 billion barrels of oil and gas off Guyana’s shores. Two ships owned by Norway’s Petroleum Geo-Services ( PGS.OL ) halted seismic survey activities after a confrontation Saturday with a Venezuelan navy vessel. The navy did not board the ships and none of the 70 […]