HOUSTON, Aug 16 (Reuters) - Los Angeles CARBOB for promptdelivery extended gains on Tuesday in active trade on continuedrefiner buying, dealers said.
* August Los Angeles CARBOB jumped 5.5 cents, trading at an8-cent a gallon premium to the NYMEX RBOB contract
* September-delivering CARBOB traded between 13.25-cent to14-cent a gallon premium to the NYMEX futures contract, up 6cents
* October CARBOB traded at a 9-cent a gallon premium to theNYMEX RBOB contract
* Phillips 66 reported unplanned flaring at its LosAngeles-area refinery on Tuesday morning, according to aregulatory filing
* Shell on Tuesday confirmed an operational upsetat its Martinez refinery near San Francisco on Saturday. Aspokesman for the company said there was no impact to refineryoperations (Reporting by Liz Hampton)