Japan's Nikkei 225 Stock Average rose Wednesday amid positive US economic data and the G7 meeting's promise of a closer collaboration to tackle economic problems.

The Nikkei climbed 1.31 percent or 110.18 points to 8,492.18 and the Topix index gained 0.2 percent to 709.33.

Among major gainers were Nippon Sheet Glass Co (5.5 percent), Olympus Corp (2.5 percent) and Toyota Motor Corp (0.6 percent). Meanwhile, shares of Nintendo declined 2.5 percent following disappointment in the market about the new Wii U games console. Shares of Green Inc also fell 0.7 percent.

The market sentiment was positive as the report announced Tuesday showed that the US services sector expanded in May over the previous month, alleviating concerns over global economic conditions for the time being. The Institute for Supply Management's (ISM) non-manufacturing purchasing managers index (PMI) rose to 53.7 in May from 53.5 in April.

Investor confidence was also boosted as G7 finance ministers had a teleconference Tuesday in which they decided to work jointly to sort out the debt crisis in Spain and Greece. But there were no major announcements of measures to tackle the problems in the euro zone.

Investors are also focusing on Wednesday's meeting of the European Central Bank, which is expected to make some announcement on interest rates to stimulate growth and ease economic concerns in the euro zone. Still sentiments are overshadowed by Spain's warning that it was losing access to credit markets, indicating its weakening financial condition.