UPDATE 5-Chile Escondida workers to end two-week strike

* Strikers vote to accept company bonus offer, lift action

* BHP Billiton refused to raise bonus, aims to set example

* Strike could herald new era of labour turbulence in Chile

(Adds copper prices)

By Moises Avila

ANTOFAGASTA, Chile, Aug 5 (Reuters) - Workers at Chile's giant Escondida mine on Friday accepted a company offer to end a two-week strike that shut down the world's top copper deposit and stoked fears of a global supply shortage.

Union leader Marcelo Tapia told Reuters workers could return to the job as soon as Friday evening to lift a stoppage that is believed to have cost owner BHP Billiton more than 40,000 tonnes of copper production.

An end to the strike could ease supply fears and add to a sharp fall in copper prices as a gloomy global economic outlook sparks a flight to save-haven assets.

Copper rose to near 4-month highs earlier this week, thanks in part to the stoppage, but has shed more than $500 in value as investors fret over a sluggish global economy.

"This (the end to the strike) might remove some of that (price) support, but I think what's going to be far more influential to prices is what happens on the macro front over the next view days," said Gayle Berry, an analyst with Barclays Capital in London.

Copper in London was trading at $9,190 a tonne at 1037 GMT from Thursday's close of $9,355, a slide of 6.5 percent on the week, which would be its biggest weekly fall since March.

The world's top miner had defied strikers, resubmitting a lower bonus offer that they snubbed last week but that aimed to set an example to workers at other mines mulling similar pressure tactics to demand more from the copper-price bonanza.

A BHP official was not immediately available to comment.

Union officials said the proposed bonus worth $5,760 fell short of workers' expectations but acknowledged strikers were tired after two weeks on the picket lines without pay.

The stoppage lasted longer than expected and forced the mine to declare force majeure -- a contract clause that frees it of liability on delivery delays -- on copper concentrate sales.

It also became a headache for unpopular President Sebastian Pinera, who is struggling with massive student demonstrations that turned violent on Thursday after clashes with police in the capital Santiago.

MORE TURBULENCE AHEAD

Soaring commodity prices have moved workers from Zambia to South Africa and Australia to demand a bigger share of the near-record profits of mining giants such as Anglo American and Freeport McMoran .

Unions at Escondida tapped into the growing discontent against Pinera, which may force him to ease on the strict fiscal discipline that has made Chile the region's most stable economy.

The strike came only days after workers at state copper giant Codelco downed tools for 24 hours to protest against massive layoff plans as part of a restructuring of the world's top copper producer.

The Escondida strike caught Chile off guard, coming outside the collective bargaining process. It has raised the possibility of increasingly unpredictable and volatile labour action in Chile, the world's top copper producer.

The world's No. 3 copper mine, Collahuasi, went through a 24-hour partial strike over the weekend. Some workers Collahuasi, which accounts for 3.3 percent of global mined copper, downed tools on Saturday over labor demands of their own but ended their protest on Sunday.

Diego Hernandez, CEO of state copper giant Codelco , the world's biggest copper producer, told Reuters in Australia on Thursday he saw some risk that unrest at Escondida could spread to other mines in Chile, but said companies would be able to manage.

“There is a risk to more industrial actions but not a big one," Hernandez said in an interview after a presentation to the Melbourne Mining Club.

The last time Escondida workers downed tools in 2006 -- for 25 days -- they had similar demands for higher bonuses linked to lofty profits. Copper prices then rallied on the stoppage.

Labour unrest and severe weather disruptions have buffeted the mining industry in Chile this year, which may cut its annual output target and deepen a global supply deficit.

Codelco's Hernandez said a string of strikes, bad weather and delayed start ups would probably drag down Chile's estimated annual output by 5 percent or up to 500,000 tonnes in 2011.

(Reporting by Santiago newsroom; writing by Alonso Soto; editing by Michael Urquhart and Keiron Henderson)