(Adds analyst comment and dateline, updates prices)

By Eric Onstad

LONDON, May 11 (Reuters) - Copper prices advanced to

their highest level in more than three months on Monday, as

worries about supply shortages outweighed concerns about lower

demand due to the stalemate in the Iran war.

Benchmark three-month copper on the London Metal

Exchange was up 0.5% at $13,637 a metric ton by 0940 GMT, its

strongest since January 29.

It was on track to notch up its sixth straight session of

gains, the longest bullish run since December. It has gained

about 10% so far this year, but is well below the $14,527.50

peak hit in January.

Copper's break above $13,500, which had been rejected

several times since February, on Friday attracted funds that use

technical levels, said Ole Hansen, head of commodity strategy at

Saxo Bank in Copenhagen.

"That price action looks pretty robust against the

not-so-robust backdrop of the war in the Middle East. That

points to supply being equally challenged at a time where demand

is called into question."

Copper also received support after Freeport delayed the full

resumption of its flagship Grasberg mine to early 2028 from the

previous expectation of late 2027.

The most-traded copper contract on the Shanghai

Futures Exchange closed daytime trading 0.9% higher at 104,620

yuan ($15,396.39) a ton, after hitting a three-month high of

104,840 yuan.

Factory inflation in top metals consumer China beat

expectations, data showed, raising hopes that the government's

efforts to boost the economy were having an impact.

LME aluminium gained 1% to $3,538.50 a ton on

persistent worries about the impact of the conflict on producers

in the Middle East, which accounts for about 9% of global

supply.

"A rapidly tightening aluminium market has left investors

questioning why the LME aluminium price has not rallied more,"

Morgan Stanley analyst Amy Gower said in a note.

Among other metals, LME zinc edged up 0.1% to $3,433

a ton, lead added 0.3% to $1,980, nickel climbed

1.6% to $19,190, and tin gained 1.4% to $54,645.

($1 = 6.7951 Chinese yuan)