* Investors cautious ahead of bank repayments to ECB
* Alex seen skirting Gulf of Mexico's main oil production
* For a technical view, click: [
]* Coming Up: U.S. API inventory report at 2030 GMT (Updates throughout, changes dateline, pvs SINGAPORE)
By Christopher Johnson
LONDON, June 29 (Reuters) - Oil prices fell 2 percent to below $77 per barrel on Tuesday as stock markets slumped and risk appetite dwindled on renewed worries over euro zone debt.
Shanghai's main equities index <
> plunged more than 4 percent, Japan's Nikkei < > was poised for its worst quarter since October-December 2008 and European stocks lost 1.5 percent in early trade as the dollar rose against the euro <EUR=>.A supportive factor for oil was removed as forecasts indicated Tropical Storm Alex would skirt the main production region in the Gulf of Mexico, limiting disruption there to a few precautionary shutdowns. [
]U.S. crude for August <CLc1> tumbled as much as $2.00 to a low of $76.25 per barrel before recovering to $76.75, down $1.50 by 1019 GMT, extending Monday's 0.77 percent decline.
Oil is still up almost a fifth from its intra-day low on May 20 below $65 and is about $10 lower than an early-May 19-month peak above $87.
ICE Brent <LCOc1> fell $1.40 to $76.19.
Investors were cautious ahead of bank repayments to the European Central Bank. Banks must repay 442 billion euros ($545.5 billion) to the ECB on Thursday, leaving a potential liquidity shortfall in the financial system of over 100 billion euros. [
]The dollar rose 0.5 percent against a basket of currencies on Tuesday. A stronger dollar makes oil more expensive for many buyers based in other currencies. <.DXY> [
]"It is a return to risk aversion," said Eugen Weinberg, a commodity analyst at Commerzbank in Frankfurt. "Gold <XAU=> is outperforming other commodities, a sign of a move to safe havens, and base metals are down on worries over the economy."
"The oil market is no longer worried about Tropical Storm Alex as it looks like it will avoid oil facilities," he said.
ALEX
The U.S. National Hurricane Center forecast that Alex, located about 520 miles (835 km) southeast of Brownsville, Texas, would make landfall near the Texas-Mexico border early Thursday. [
]Alex, which was moving slowly north-northwest, is expected to strengthen into the first hurricane of the Atlantic season on Tuesday, the NHC said in latest advisory on Monday.
A tropical storm, where the maximum sustained surface wind speed is 63-118 km per hour (kph) (39-73 mph), is weaker than a hurricane, where sustained winds are 119 kph or faster.
Shell <RDSa.L> said it was shutting output from its western and central Gulf of Mexico assets ahead of Alex. [
]