* First Quantum says 85.5 pct of shareholders tender to bid
* Continues consolidation among copper miners
* Says can keep to Inmet schedule on Cobre Panama
* Sees "full pipeline" but more deals possible
TORONTO/LONDON, March 22 (Reuters) - First Quantum Minerals Ltd said on Friday it had won enough shareholder support to take over Inmet Mining Corp, winning a C$5.1 billion hostile battle for control of one of the world's largest untapped copper deposits.
The deal - the latest in an industry that has concentrated to leave ever fewer pure copper miners behind - creates one of the world's biggest producers of the red metal.
It also transforms First Quantum, which until now has made more than 80 percent of its profit in Zambia.
First Quantum, for its part, faces arguably its toughest test to date in Inmet's $6.2 billion Cobre Panama project, the jewel in the miner's crown.
Cobre Panama is one of the biggest untapped copper deposits in the world, but also one of the most expensive - in an untested country with little mining history.
"They've certainly shown themselves to be very efficient and effective project managers in the past, successfully executing on what much larger firms have struggled with," said Daniel Rohr, a mining analyst at Morningstar.
First Quantum, which cut its teeth in Zambia as the country re-privatised its mines in the 1990s, is betting its hands-on approach to construction, procurement and supervision will help slash costs at Cobre Panama while keeping to deadlines.
"There will be a hiatus of three to six months, whatever it takes to do a comprehensive reassessment and renegotiations where required. But our build time will be much shorter," First Quantum President Clive Newall told Reuters.
"We have a two-year construction phase (at) our projects, so we will be able to stick pretty closely to Inmet's schedule, which was for commissioning at the end of 2016 or the beginning of 2017."
Newall dismissed concerns that Inmet's existing contracts might have locked in high costs. But he said it would be "several months" before the group could publish specific targets and its own plan for the mine, where challenges include heavy tropical rainfall.
The deal is the latest in a copper industry where rising costs and a dearth of new deposits have prompted consolidation, leaving only a handful of mid-sized base metals producers such as HudBay Minerals Inc and Lundin Mining Corp.
Poland's KGHM sealed a C$3 billion takeover of Quadra FNX in 2012, while Barrick Gold Corp's C$7.3 billion deal to acquire Equinox Minerals in 2011 took yet another mid-sized base metal company off the market.
With Cobre Panama and its own development projects coming on stream over the next five years, First Quantum now expects to be producing some 1.3 million tonnes of copper annually by 2018, making it one of the top five producers in the world.
Newall said that while First Quantum has no plans to trim its own portfolio, more deals were not off the cards, as major mining companies streamline portfolios and put dozens of assets up for sale, including copper deposits.
"We have a pretty full pipeline for the next few years, but that doesn't mean we'll stop looking," he said. "There is going to be a period, over the next year to 18 months, where there are going to be some opportunities. It is just that we will be setting the bar ever higher."
First Quantum said in Friday's statement that a total of 60.1 million Inmet shares, representing about 85.5 percent of outstanding shares, had been tendered in favor of its offer.
The offer has been extended to 5 p.m. EDT (2100 GMT) on April 1. If able to secure 90 percent of the shares, First Quantum will proceed with a compulsory acquisition.
Toronto-based Inmet, which rejected First Quantum's advances for months, recommended on Friday that shareholders tender their shares to the offer. The miner also announced the resignation of its entire board and named four First Quantum officers to the new board.
Jefferies International, Goldman Sachs and RBC Capital Markets acted as financial advisers for First Quantum on the deal, while Fasken Martineau DuMoulin acted as legal counsel.
First Quantum's shares closed down 2.3 percent at C$20.12, while Inmet's shares closed 1.5 percent lower at C$69.11 on the Toronto Stock Exchange.