* Q2 adjusted EBITDA jumps to $568 mln
* Sees global aluminium surplus of 277,000 tonnes in 2015
* Expects Chinese semis exports to fall in H2 (Adds details about board meeting on dividend)
By Sonali Paul
Aug 27 (Reuters) - Russia's Rusal 0486.HK has decided to delay a decision on its possible first dividend since listing five years ago though its second-quarter core profit more than doubled thanks to cost cuts and a weaker rouble.
The rouble's decline supports the world's top aluminium producer by partially offsetting weak aluminium prices, which are already at six-year lows and, according to Rusal, will remain under pressure due to a glut of exports from China.
"We expect that (the) aluminium market is likely to remain challenging for the remainder of the year," Chairman Matthias Warnig said in a statement.
Rusal's core profit, or adjusted earnings before interest, tax, depreciation and amortisation (EBITDA), soared to $568 million for the three months to June from $220 million a year earlier, topping analysts' forecasts of around $467 million.
The market had thought Rusal would announce its first dividend since listing in 2010, after it said earlier this month that was under consideration. Its net debt fell $600 million from the end of March to $8 billion at the end of June.
Rusal's board of directors adopted a new dividend policy on Aug. 26, but decided to delay the decision on dividend payment, the company said. ID:nASB0A4GC
The board will consider the dividend question by the end of September, Interfax news agency quoted the company as saying.
Its shares were up 1 percent by 0851 GMT.
Rusal predicted global supply would outstrip demand by 277,000 tonnes in 2015, but that was less bearish than U.S. rival Alcoa's AA.N forecast for a surplus of 760,000 tonnes this year.
It said it doubted Chinese producers would increase exports of semi-manufactured aluminium products, such as plates for window frames and beer cans, as those shipments were already loss-making.
Rio Tinto RIO.AX RIO.L said recently that sliding London Metal Exchange prices and shrinking premiums - surcharges paid on top of LME prices for metal delivery - had driven 40 percent of the industry's smelters back into the red.
That has led producers to consider cutting smelter capacity again, adding to reductions over the past two years. Glencore's Century Aluminum Co CENX.O this week said it would idle a plant in Kentucky. ID:nL2N0SB1UE ID:nL1N1102C7
Rusal expects to decide later this year on plans to cut 200,000 tonnes per year of capacity. However, the company is still on track to start its new Boguchansk smelter in Russia by the end of 2015. ID:nM0N0V800R