May 19 (Bloomberg) -- Woodside Petroleum Ltd. and Santos Ltd., Australia's second- and third-largest oil and gas producers, rose to records in Sydney trading amid expectations increases in oil-price forecasts will lead to earnings upgrades.

Woodside, based in Perth, gained A$6.30, or 10 percent, to close at A$69.50 on the Australian Stock Exchange after reaching an all-time high of A$70.20 earlier in the session. Adelaide- based Santos advanced A$1.26, or 6.8 percent, to A$19.76.

UBS AG last week boosted its 2008 forecast for West Texas Intermediate, the U.S. benchmark crude variety, by 32 percent to $115 a barrel and its 2009 and 2010 forecasts by 54 percent and 53 percent, respectively. It raised its 12-month share price forecast for Woodside by 16 percent as a result, by 24 percent for Santos and by 18 percent for Port Moresby-based Oil Search in a May 15 report.

``We've seen strong solid increases in oil prices for a number of weeks now,'' said Gavin Wendt, senior resources analyst at Fat Prophets Funds Management in Sydney. ``There's been a healthy degree of skepticism on the part of a lot of big fund managers and big brokers with regard to the sustainability of the oil price. Perhaps some of them are starting to change their view.''

Crude-oil futures in New York have gained 34 percent in the past six months, and 91 percent in the past year. Oil Search Ltd., Papua New Guinea's biggest petroleum producer, also reached a record in Sydney trading, rising 3.3 percent to A$6.30.

Goldman Sachs Group Inc., the world's biggest securities firm by market value, last week raised its New York crude-oil price forecast for the second half of the year by 32 percent, citing supply constraints. It now forecasts West Texas Intermediate will average $141 a barrel in the second half, rising to an average of $148 next year.

Woodside is 34 percent owned by Royal Dutch Shell Plc. BHP Billiton Ltd. is Australia's biggest oil and gas producer.