Markets were mostly higher on Thursday after U.S. Federal Reserve May meeting minutes indicated an unwinding of its balance sheet likely towards year-end and as investors look ahead to an OPEC gathering widely expected to extend output cuts.

Minutes released yesterday indicated that the Fed could use a system where cap limits are implemented on how much the Fed would roll off every month without reinvesting. The central bank's balance sheet is currently worth $4.5 trillion.

While the Fed signaled that interest rates could be raised soon, Federal Open Market Committee (FOMC) members also indicated in the minutes that "it would be prudent" to wait for more evidence that reflected the softer economic data out of the U.S. recently was transitory.

National Australia Bank Economist Tapas Strickland said in a Thursday morning note that the trajectory for interest rates after the likely June hike were "slightly more uncertain" due to inflation outlook from the Fed.

The dollar fell while stocks rose following the release of the minutes. The dollar index (New York Board of Trade (Futures): =USD), which measures the dollar against a basket of rival currencies, traded as low as 97.093 after the news.

"A modest post-release fall in the dollar suggests messaging from the Fed was slightly less hawkish than some feared," CMC Markets Chief Market Strategist Michael McCarthy said.

The dollar index sank to 97.010 at 9:58 a.m HK/SIN.

The Nikkei 225 (CBOE: .NKXQ) gained 0.42 percent while South Korea's benchmark Kospi (Korea Stock Exchange: .KS100) index surged 0.9 percent.

Down Under, the ASX 200 (ASX: .AXJO) was steady, edging higher by 0.28 percent.

Markets in greater China opened mixed a day after Moody's downgraded the credit rating of the world's second largest economy. Hong Kong's Hang Seng Index (Hong Kong Stock Exchange: .HSI) was up 0.41 percent. The Shanghai Composite (Shanghai Stock Exchange: .SSEC) shed 0.27 percent while the Shenzhen Composite dipped 0.232 percent.

Indonesian markets were closed for a holiday.

Markets are also likely to be watching the highly-anticipated OPEC meeting in Vienna . Major oil producers are expected to extend, and potentially deepen, output cuts in a bid to rebalance bloated oil markets.

While U.S. West Texas International (WTI) crude will likely gain if output cuts are extended, FXTM Research Analyst Lukman Otunuga said oil prices remained caught between optimism over the OPEC-led deal and U.S. shale limiting upside gains.

"I believe that U.S. shale is a significant threat to the OPEC deal, especially when considering how the surging output from the U.S. has seized market share from other OPEC members ... While it may be too early to say that this is the end of OPEC, U.S. shale has considerably weakened the cartel's grip on the global markets," Otunuga said in a Wednesday note.