GLOBAL MARKETS-Euro slides to two-decade low as recession fears mount

* Euro back at 2002 levels after gas price surge, weak data

* Wall St futures down after U.S. holiday

* RBA raises but Aussie falls sharply

* Graphic: Global asset performance http://tmsnrt.rs/2yaDPgn

* Graphic: World FX rates http://tmsnrt.rs/2egbfVh

By Tommy Wilkes

LONDON, July 5 (Reuters) - The euro sank to its weakest since late 2002 versus the dollar on Tuesday, as a jump in natural gas prices reignited worries about the euro zone economy and data showed business growth in the region slowed sharply in June.

After the U.S. markets were closed for a holiday on Monday, Tuesday was proving to be a much more volatile session, with stocks reversing early gains and euro zone bond yields falling as investors sought out safety in government debt.

News that Norwegian offshore workers began a strike on Tuesday that will reduce oil and gas output has added to fears about a European energy shortage.

The euro dropped by as much as 1.3% against the dollar to $1.0281, its weakest since December 2002. Versus the Swiss franc, it dropped 0.9 %to 0.9925 francs, its lowest since 2015.

The dollar index shot up 1.1% to 106.26, a two-decade high for a currency that investors rush to buy during times of acute economic uncertainty.

"Everyone is gearing up for Nord Stream to be turned off and Russia has already signaled they will use that as a weapon. So this is really hitting the competitiveness of German manufacturing," said Jordan Rochester, a currencies analyst at Nomura.

"Germany has way higher manufacturing, so we are facing a supply crunch of energy, rationing, so the euro area's competitiveness will collapse and its exports will be curtailed."

Survey data on Tuesday showed business growth across the euro zone slowed further last month and forward-looking indicators suggested the region could slip into decline this quarter as the cost of living crisis keeps consumers wary.

Elsewhere, stock markets gave up early gains as the surge in natural gas prices weakened sentiment, offsetting earlier optimism about signs of easing U.S.-China trade tensions.

Wall Street looked set for a weaker open . The Euro STOXX was last down 0.55% while Germany's DAX fell 0.9%. The FTSE 100 dropped 1.1%.

The MSCI World Index declined 0.31%, still 3% off 18-month lows hit in June.

BRIEF RESPITE

Offering brief respite to nervous markets earlier was a report that U.S. President Joe Biden was leaning towards a decision on easing tariffs on goods from China.

A survey showing China's services activity grew at the fastest pace in almost a year also helped the mood during Asian hours.

Tuesday offers little in the way of important economic data, but later this week the U.S. Federal Reserve and European Central Bank release their minutes from recent policy meetings and on Friday widely watched U.S. payrolls data is published.

"Markets are all about recession risk," said Grace Peters from JPMorgan Private Bank, pointing to evidence that consumers had changed their behaviour since June.

"The data since then whether U.S. mortgage markets or PMIs (purchasing managers index surveys) or consumer confidence shows that economic momentum has worsened considerably in Q2. That's really driving cross asset moves," Peters said.

Australia's central bank hiked rates again with a second straight 50 basis points increase.

However, the Aussie dollar fell 1.3% to as low as $67.82 as investors interpreted the bank's accompanying messaging to be more dovish than expected and as the U.S. currency gained across the board.

In South Korea June inflation accelerated to its fastest since the Asian financial crisis, fanning expectations the central bank could deliver a 50 basis point rate rise for the first time next week.

U.S. Treasury yields returned from the holiday little changed, with the yield on benchmark 10-year notes at 2.92%, below the 3%-plus levels of last week.

Euro zone government bond yields fell two to five basis points on uncertainty about the future path of monetary tightening by the European Central Bank and as investors fearful of the economic outlook sought safety.

As economic fears spread across markets, oil prices dropped in sympathy. Brent crude futures weakened 1.53% to $111.76 a barrel after earlier trading higher. U.S. crude oil lost 0.41% higher to $107.99 a barrel.

Spot gold slipped 0.6% to $1,798 an ounce.

Bitcoin shed 2.4% to $19,720.

(Additional reporting by Dhara Ranasinghe and Sujata Rao in London and Kane Wu and Alun John in Hong Kong; Editing by Robert Birsel and Barbara Lewis and Chizu Nomiyama)