* Atlas Iron stock plummets after trading resumes
* Feeling pain from collapse in iron ore price (Adds quote, debt yield move, closing share price)
By James Regan
SYDNEY, July 27 (Reuters) - Shares in Australian miner Atlas Iron Ltd AGO.AX tumbled 70 percent on Monday after the stock resumed trading following a four-month hiatus caused by the collapse in iron ore prices.
The shares closed at 3.6 Australian cents, well under the 12 cents when the stock went into a trading halt on April 2 and a sliver of the 71 cents they were worth this time last year
"Coming back online today meant that every shareholder that was waiting for them to come back chose to make a massive loss and get out," said IG markets strategist Evan Lucas.
Earlier this month Atlas raised less than half the A$180 million ($131 million) it had sought in a share offering, despite the new shares being discounted to 5 Australian cents each, with a free option at 7.5 Australian cents.
Its contractors took up $40 million of the new shares, with many of Atlas's roughly 33,000 small investors buying the rest.
Atlas suspended mining when the iron ore price fell to $47 a tonne, saying it was losing $15 on each tonne it mined. It has since established a $50 break-even price, helped by a profit-sharing arrangement with its contractors.
The last of its three mines reopened this month.
Iron ore .IO62-CNI=SI stood at $50.70 a tonne on Monday.
Atlas is now selling a minimum of 80 percent of its output at fixed forward prices of between $52 and $59 a tonne using a variety of hedging instruments, although the contracts are reset each quarter.
Fiscal 2016 production and cost guidance will be unveiled when Atlas releases a quarterly operations report on July 31.
Small producers such as Atlas are being hurt by tumbling ore prices as big miners BHP Billiton BHP.AX BLT.L , Rio Tinto RIO.L RIO.AX and Fortescue Metals Group FMG.AX ramp up production to try to squeeze out high-cost mines in China, where they have been expanding.
Average bids for an Atlas Iron $275 million term loan dropped to 34 percent of par value in the secondary market on Friday. That compares with 50 percent in April, according to Thomson Reuters Secondary Market Intelligence. ID:nRLP34773a
($1 = 1.3729 Australian dollars)