* Falling oil prices, increased tariffs on pipelines hurt results
* Rise in rebel attacks has also hit operations
* But Q2 oil and gas output up 2.1 pct yr-on-yr (Adds detail)
BOGOTA, July 31 (Reuters) - Colombian state oil company Ecopetrol’s net profit fell 6.8 percent to 3.4 trillion pesos ($1.8 billion) in the second quarter from a year ago, as the price of oil slipped, transport costs rose and it was forced to spend on repairs after rebel attacks.
Oil and gas production by the group, which includes operations outside Colombia, was 778,100 barrels of oil equivalent per day (boepd) in the quarter, up 2.1 percent from the same period last year, Ecopetrol said in a statement.
Ecopetrol said that second-quarter consolidated operating profit fell 1.1 percent to 5.9 trillion pesos versus a year ago.
Earnings before interest, tax, depreciation and amortization increased 1.3 percent in the second quarter, good for an EBITDA margin of 43 percent versus 45 percent a year before, it said.
Like other companies operating in Colombia, Latin America’s No.4 oil producer, Ecopetrol has been hit by a rise in rebel attacks against oil facilities, delays in getting key permits and an increase in social protests that have blocked roads.
A decade-long offensive by U.S.-backed troops against the Revolutionary Armed Forces of Colombia, or FARC, has pushed them deeper into inhospitable jungles and mountains, but the rebels still attack military and civilian targets, especially against the oil and mining sectors.
Transport costs rose during the quarter due to increased tariffs on pipelines, Ecopetrol said. (Reporting by Helen Murphy; Editing by Joseph Radford)