Singapore Exchange (SGXL.SI) unveiled an agreed A$8.4 billion ($10.7 billion) takeover of Australian bourse operator ASX Ltd (ASX.AX), marking the first major consolidation of exchanges in the Asia-Pacific region.

SGX, Asia’s second-largest listed bourse, offered a combination of A$22.00 in cash plus 3.473 of its own shares for each ASX share. It said in a joint statement with the ASX on Monday that the offer valued ASX shares at A$48.00 each, a 37% premium to ASX’s last trade.

Both SGX and the ASX are under pressure to expand and find new business opportunities and counter the threat of alternative trading systems. ASX has also been looking at new opportunities ahead of the end of its monopoly in 2011.

SGX is 23% owned by the Financial Sector Development Fund which is controlled by Singapore’s central bank.