Roberto Cobaria, chief of the U'wa tribe in Colombia, met with Occidental Petroleum Corp. executives at the Airport Hilton in Los Angeles to try to persuade them not to drill for oil on land near the U'wa reservation. Westwood-based Oxy has government clearance to drill at the site, which is not on U'wa property. But the 5,000-member U'wa tribe has threatened mass suicide if drilling proceeds. Cobaria complained there was "no dialogue" at Tuesday's meeting, and he invited Oxy executives to visit the U'wa reservation. Oxy Executive Vice President James R. Niehaus said in a statement: "We were pleased to have the opportunity to meet Mr. Cobaria face-to-face. . . . We expressed our desire to examine at a future date a wide range of actions to determine how [the U'wa] concerns might be addressed." Oxy shares rose 12.5 cents to close at $22.625 on the NYSE.