WRAPUP 1-National oil firms warn $60 oil threatens supplies

* State-owned oil firms sticking to investment plans for now

* Marginal cost of new oil is $60 a barrel - Petrobras

* Long recession risks project cutbacks, shortage in 2 years

By Chua Baizhen and Emma Graham-Harrison

BEIJING, Nov 7 (Reuters) - The world's biggest state-owned oil companies are weathering the global financial crisis and the dive in crude prices for now, top executives said on Friday, but they warned that $60 oil could soon begin to stymie their investment.

Oil majors and public energy firms that have ventured into higher-cost frontiers to grow their production are already beginning to pull back on projects as credit grows scarce and oil's steep retreat in recent months threatens their profits.

But for now national oil firms -- backed by political will and, in many cases, government coffers overflowing after a five-year oil boom -- are holding the line, even though they say prices are nearing unprofitable levels.

"We're not satisfied as a company with current oil prices," Mohamed Meziane, chief of Algeria's state oil firm Sonatrach, told reporters in Beijing, where he was attending a closed-door global forum for national oil company executives.

"We would like to have a higher oil price, at $80 to $100 a barrel, to satisfy all the concerned consumers and producers."