* Petrobras removes 317 gallons of spilled oil from beach
* Steelmaker CSN spills oil into major Brazilian river
* CSN says spill of estimated 13,000 gallons "contained"
RIO DE JANEIRO, Jan 27 (Reuters) - Brazilian oil giant Petrobras cleaned up around 317 gallons (1.2 cubic meters) of oil that washed ashore from a leaking terminal buoy onto a southern Brazilian beach on Thursday, the company said.
Transpetro, the shipping unit of Brazil's state-run oil firm, said on Friday it cleaned up oil from the Tramandai beach in Rio Grande do Sul State, in Brazil's far south, and is investigating what caused the spill.
The oil leaked on Thursday from a buoy used to connect oil tankers to a pipeline at Transpetro's coastal Osorio terminal in the area. The storage facility serves Petrobras' Alberto Pasqualini refinery in Canoas, Brazil.
Oil spill containment crews remain on site, although Petrobras said there is no sign of more oil in the water near the buoy.
CSN OIL SPILL
Separately, Brazilian steelmaker CSN reported an oil spill on Thursday into the Paraiba do Sul River in Rio de Janeiro State, near its Presidente Vargas steel mill.
A company spokesman said CSN doesn't have an official estimate of the spill volume. However, he said it could be around 50 cubic meters (13,209 gallons) of oil.
The spokesman said the spill was contained by a barrier in the river, which serves as a major source of drinking water for Rio de Janeiro state. CSN said the spill does not pose risks to drinking water supplies because it is contained.
A 2009 oil spill by CSN into the same river led to a 5 million real ($2.8 million) fine, O Globo newspaper reported on Friday. CSN also spilled charcoal waste into the river in 2010, resulting in a 20 million real ($11.2 million) fine, the paper said. (Reporting By Joshua Schneyer; Editing by Jeb Blount, Phil Berlowitz)