UPDATE 2-Petrobras cuts goal for 2012 Brazil oil output

* Petrobras aims for 336,000 bbl/day more oil from Brazil

* Goal cut from previous 480,000 bbl Brazil new oil in 2012

* Petrobras cuts P-55 oil ship from list of 2012 output

RIO DE JANEIRO, Feb 14 (Reuters) - Petrobras , Brazil's state-controlled oil company, cut its 2012 target for additional oil output by 30 percent on Tuesday, citing delays in building a ship.

The company said it would add 336,000 barrels of new oil output a day in Brazil this year, down from its previous estimate of 480,000.

The largest part of the new output will come from Petrobras' P-57 floating production unit, which the company expects to produce 150,000 barrels of oil a day in 2012, Chief Financial Officer Almir Barbassa said in a conference call with investors.

Among the factors behind the new output estimate are delays in the completion of the 180,000-barrel-a-day "P-55" production ship being converted for use in the Roncador offshore field northeast of Rio de Janeiro.

In November, Petrobras said the P-55 would start service in the fourth quarter of 2012. Output from the floating production, storage and offloading, or FPSO, vessel is no longer on Petrobras' list detailing new output for 2012.

Maria das Gracas Foster, who took over on Monday as chief executive officer of Petrobras, said increasing production would be her priority. [ID:nL2E8DDGJD}

She takes over after sluggish production caused Petrobras' profit to fall 52 percent in the fourth quarter. Despite a $225 billion, five-year investment plan, output in December was lower than it was a year earlier, and many projects are behind schedule. [ID:nL2E8DA1K4}

Rio de Janeiro-based Petrobras, the world's No. 5 integrated oil company by market value, plans to nearly triple output to 6.4 million barrels of oil and natural-gas equivalent a day by sometime in 2020, according to the company's investment plan.

Petrobras' Brazilian output, plus that of companies such as OGX Petroleo, Shell, Chevron and BP , are expected to lift Brazilian oil and natural gas production to more than 7 million barrels a day, allowing the country to challenge the United States for the rank of world No. 3 oil producer after Russia and Saudi Arabia.

Petrobras preferred shares, the company's most-traded class of stock, fell 1.5 percent to 24 reais ($13.95) in trading in Sao Paulo.