METALS-Copper slips, aluminium climbs as Iran war rumbles on

March 24 (Reuters) - Copper slipped on Tuesday, giving up some of its gains in the previous session's relief rally, while aluminium jumped as the conflict in the Middle East continued despite U.S. President Donald Trump postponing his threat to bomb Iranian power plants.

Benchmark three-month copper CMCU3 on the London Metal Exchange was down 0.5% at $12,105 a metric ton at 1700 GMT. It closed up 2% on Monday after Trump spoke of "very good and productive" negotiations with Tehran on ending the war.

"Copper is easing today after yesterday's bounce, as geopolitical optimism faded," said ING commodities strategist Ewa Manthey.

A rebound in oil prices LCOc1, together with a firmer dollar .DXY, pressured industrial metals by raising fears that central banks will have less room to cut rates and that higher fuel costs will sap global growth.

The Iran war is already taking a toll on major economies around the world, according to business surveys.

Citi now expects copper to fall to $11,000 a ton in the next three months, compared with $14,000 previously.

"We expect industrial metals to grind lower while the Hormuz Strait remains closed, as investors discount Fed rate cuts and cyclical growth expectations and continue broad de-risking across risk assets," the bank said.

Elevated LME copper stocks MCU-STOCKS of 359,275 tons, the highest in almost eight years, were also weighing on prices. The spread between the cash LME copper contract and the three-month forward CMCU0-3 remains in a contango of around $93 a ton.

Still, renewed buying interest in top consumer China - where exchange copper stocks fell 5.2% last week - is "helping to limit the downside", Manthey added.

Aluminium CMAL3 climbed 1.6% to $3,249.50 a ton on fears smelters in the region, which accounts for around 9% of global supply, will continue to struggle to ship metal out.

Zinc CMZN3 fell 1.2% to $3,041, lead CMPB3 lost 0.4% to $1,892, nickel CMNI3 slipped 0.7% to $16,960, and tin CMSN3 gained 0.7% to $43,755.