NEWS CORPORATION is to unveil new online jobs and auction sites in the UK early in 2000 as part of a planned strategy to increase its presence on the internet. The newcomers are likely to be branded separately from News Corp's newspaper sites but will be promoted heavily in its press titles. News Corp also revealed that the boom in online start-ups had increased its overall ad revenues in the United States by 'several hun-dred million dollars this year - and the single biggest contributor is ‘dot com' advertising