* Q1 production falls 19 pct
* FY guidance unchanged at 63-66 MMboe ex-Pluto
* Tested market for Laminaria-Corallina sale but will not proceed with deal
* Shares down 1 pct (Adds detail)
SYDNEY, April 19 (Reuters) - Australian oil and gas firm Woodside Petroleum warned on Tuesday that its flagship Pluto LNG project could be delayed because of weather-related problems, but left its start-up and production targets unchanged.
Woodside said its A$14 billion, 3.6 million tonne-per-year Pluto project had suffered a four-week delay because of heavy rains and cyclones over the Australian summer but start-up was still scheduled for August with first gas a month later.
"The end of the cyclone season is approaching and will result in a better work environment. Mitigation plans are in place but it may be hard to recover weather-related delays at this late stage in the project," Woodside said in a statement.
Share markets mostly ignored the warning, sending Woodside shares down 1 percent, in step with the broader market .
Woodside, 24.3 percent owned by Royal Dutch Shell
But its annual production was on track for 63 to 66 millions of barrels of oil equivalent (MMboe) with Pluto contributing an additional 5-9 MMboe.
"Average daily production rates from the Australia oil assets during Q1 were materially lower than normal due to the increased tropical cyclone activity in the North West," it said.
"With the approaching end to the cyclone season, at the end of the quarter, production rates have returned to typical levels," it added.
Woodside also said it had tested the market to sell its Laminaria-Corallina field, which suffered a 30 percent year-on-year production drop in the first quarter, but decided to keep the asset in view of high oil prices. (Reporting by Balazs Koranyi; Editing by Mark Bendeich)