* Mine extends deadline for strikers to take offer
* Mine hopes to lure workers off picket line
* Union says company must resume talks to end walkout
(Adds management saying output normal)
By Fabian Cambero
IQUIQUE, Chile, Nov 24 (Reuters) - The world's third largest copper mine on Wednesday gave workers more time to accept a contract offer designed to lure the majority back to work and break a 20-day-long strike.
Officials at the Collahuasi mine, owned by Xstrata and Anglo American, had said the wage offer will expire at midnight (0300 GMT) on Tuesday.
But they extended the deadline for three days to late on Friday after a vast majority of workers stayed out.
If more than half of workers take the offer, which includes a one-off bonus of $29,000, then the strike will effectively end.
"This is a product of the systematic misinformation afflicting our workers," said a statement from management.
Management said that workers needed more time to consider the offer, and said the bonus will be lowered to $25,000 starting on Saturday.
The union has displayed banners that say "miners stay strong" in its headquarters. The management has used local radio to call on workers, who are not being paid while on the picket line, to accept the proposal and return.
Union leaders said workers will picket until management agrees to revive stalled talks, but the management has said it latest offer is final.
Officials say that so far only 170, or just 11 percent of 1,551 striking workers, have gone back to work. The union says just a few dozen workers have quit the strike, held as copper prices flirt with record highs.
The union said the walkout would not wither.
"We hope the company reconsiders its position and sits down to talk with us.
The company has to realize that its objective was not achieved today," said Manuel Munoz, head of the union.
The strike is the biggest at a privately held mine in Chile since 2006. A regional appointee of conservative President Sebastian Pinera has called on both sides to resume talks.
Under Chilean law, if talks at Collahuasi are reopened, the point of departure for negotiations would be the last offer the union voted on.
That package, which was overwhelmingly rejected in October, offered $19,000 in bonuses per worker and the union would likely demand a much more lucrative offer.
The mine says its latest offer would increase average wages for a new 40-month contract by 16.4 percent.
Collahuasi workers have stayed on the picket line even as miners at the nearby Los Pelambres pit accepted a less lucrative deal last week.
Collahuasi said on Wednesday copper output and deliveries remained normal under a contingency plan that includes temporary workers.
Mine officials say 44,000 tonnes of wet copper concentrate was shipped to Japan late on Monday. That is equivalent to nearly 12,000 tonnes of refined copper, or a week's worth of production.
The shipment could reduce the risk of it declaring force majeure -- a contract clause that enables the seller to default on delivery obligations.
But the union says the strike has hit output and claims the mine is running at 20 percent of capacity. (Writing by Terry Wade, Alonso Soto and Eduardo Garcia; Editing by William Hardy)