NEW YORK, USA - OIL prices jumped US$5 (S$7) to a record high above US$147 (S$199) a barrel on Friday amid growing worries about threats to supplies from Iran and Nigeria and a strike by Brazilian oil workers next week.

Analysts said oil's rally could run further if problems with United States mortgage companies Fannie Mae and Freddie Mac feed into the commodities boom by reducing the chances of an interest rate hike by the US Federal Reserve.

The troubles with the mortgage giants - which control US$5 trillion in debt - helped pare crude's gains after it hit new highs as dealers focused on US economic turmoil that has already slowed oil consumption in the world's top energy user.

'I'm seeing profit-taking here after the run-up to a new record, but we are going into a weekend and with all these things being reported on Iran, you wouldn't want to go short,' said Mr Daniel Flynn, an analyst at Alaron Trading.

In addition, Iraq's Defence Ministry said on Friday that it had no knowledge of Israeli air force drills in its airspace, contrary to a media report carried on the Jerusalem Post website that sparked crude early on Friday. An Israeli security source also said the report was wrong.

'As martial rumours are denied, participants are reverting their gaze on the deteriorating global economy,' said Mr Mike Fitzpatrick, vice-president at MF Global in New York.

Missile tests this week by Iran, against a backdrop of rising tensions with Israel and the United States, has left the oil markets worried about a potential supply disruption from the world's No. 4 exporter.

Iran has threatened to strike back at Tel Aviv and US interests in a key oil shipping route if it is attacked over its nuclear program, which Israel and the West fear is aimed at making weapons.

Support also came from supply threats in Nigeria and Brazil. The main militant group in Opec nation Nigeria's oil-producing region said it was abandoning a cease-fire to protest against a British offer to help tackle lawlessness.

Workers at Brazil's Petrobras plan to launch a five-day strike on Monday that would affect all 42 Campos basin offshore platforms, which pump than 80 per cent of the nation's 1.8 million bpd of output.

Oil prices have risen seven-fold since 2002 amid surging demand from China and other emerging markets, and jumped 50 per cent this year alone, battering the economies of consumer nation's already hit hard by the global credit crunch.

Concern in the United States that Fannie Mae and Freddie Mac could run short of capital added to inflation worries.