Japan's Nikkei share average fell on Wednesday morning as investors continued to shun riskier assets ahead of potentially market moving global events this week.

The Nikkei dropped 0.2 per cent to 19,931.43 points by midmorning. It hit a near two-year high of 20,239.81 last Friday, breaking above the psychologically important 20,000-mark for the first time since December 2015. But trade was thin, with investors awaiting Britain's general election, a European Central Bank policy decision and former FBI director James Comey's Senate testimony all due on Thursday. China is also releasing a raft of data this week. “The overall market is quiet today and the market is especially focused on Comey's testimony,” said Hikaru Sato, a senior technical analyst at Daiwa Securities.

He added that there is a risk of the dollar's falling against the yen if the outcome of Comey's testimony hinders US President Donald Trump's proposed tax overhaul and his broader economic stimulus agenda. Comey was investigating whether Trump's presidential campaign and Russia colluded to sway the 2016 US election when he was fired by Trump in May.

On Wednesday, the dollar was little changed at 109.50 yen , failing to give the market a direction.

Exporters were mixed, with Toyota Motor Corp falling 0.2 per cent, Honda Motor Co dropping 0.6 per cent and Advantest Corp rising 0.5 per cent. Banks and insurance companies, which hunt for higher-yielding products, lost ground on falling US Treasury yields. Mitsubishi UFJ Financial Group dropped 0.2 per cent, Mizuho Financial Group shed 0.5 per cent, and T&D Holdings slid 1.1 per cent.

Bucking the trend, Japan Display Inc soared 8.7 per cent after the Nikkei business daily reported the company will unveil a new medium-term plan by August under new management, to be appointed on June 21 at its annual shareholders meeting.

The firm is scrapping a modest reform plan that failed to right the ship and is embarking on a wholesale reorganization, revamping domestic production sites and even exploring a capital partnership with a peer, the Nikkei said. The broader Topix shed 0.1 per cent to 1,594.31 and the JPX-Nikkei Index 400 declined 0.2 per cent to 14,212.56.