Federal Reserve
The Federal Reserve is widely expected to raise base rates by half a percentage point on 15 March Reuters

Most stock markets across Asia were in the red on 15 March as investors await the outcome of a Federal Reserve interest rate policy meeting.

Risk sentiment was dampened with analysts widely expecting the base interest rate to be raised by half a percent, pushing it to a range of 1% to 1.25%.

Tokyo's Nikkei 225 benchmark index fell 0.3% to 19,545.21 points at mid-day.

"The progressive improvement in both labour market conditions and lift in inflation rates in the US certainly validates the Fed's move this week," said Jingyi Pan, market analyst at IG in Singapore.

Investors are looking for clues on how much the Fed plans to tighten monetary policy through this course of this year.

"Questions on both extremes have been widely discussed. On one hand, the market ponders a surprise hold, in which, massive unwinding of positions could take place with the hike already priced in," Pan said.

"On the other hand, concerns have also been paid to an acceleration in the Fed's path to normalisation, where the likelihood of four fed hikes have been raised, up from the current projection of three."

Toshiba shares slump

Shares in Toshiba plunged more than 12% after it said it may sell its majority stake in US nuclear unit Westinghouse, which is facing cost overruns at its reactor projects in Georgia and South Carolina.

The conglomerate has been given permission by Japanese regulators to delay releasing its third-quarter results until 11 April.

In February, the company announced a $6.3bn (£5.2bn) writedown on its nuclear business.

Meanwhile, mainland China's Shanghai Composite share average was up 0.1% to 3,241.97 points, while Hong Kong's Hang Seng benchmark was flat at 23,815.03.

In South Korea, the Kospi index retreated 0.1% to 2,131.11 points after official figures showed the country's jobless rate rising to 4% in February from 3.6% in January.

Elsewhere, Australia's S&P/ASX 200 benchmark was up by 0.2% at 5,771.50 points.