Japan's Nikkei share average scaled a record high on Monday, supported by upbeat performances in pharmaceuticals, as market sentiment continued to run high after the benchmark index broke the 1989 all-time peak last week.

The Nikkei was up 0.54% at 39,309.80 by the midday break. The index climbed as high as 39,388.08 to secure an all-time peak after the market resumed trade following a holiday on Friday.

The broader Topix was up 0.84% at 2,683.08.

The new high comes after the index on Thursday breached levels last seen in 1989 during the halcyon days of the bubble economy.

Japanese stocks have surged on the back of cheap valuations and corporate reforms, which have succeeded in luring back foreign money looking for alternatives to battered Chinese markets. The index has gained 16.8% so far this year.

The Nikkei got further momentum as the S&P 500 and Dow Jones Industrial Average, which are closely tracked by Japanese investors, ended at record highs on Friday.

Gains were relatively broad on Monday, with 136 of the Nikkei's 225 constituents advancing against 87 decliners.

"The overall market is in an uptrend, but within this uptrend ... there's a sense that traders are picking out the shares that are running behind and haven't been bought as much," said Hiroshi Namioka, chief strategist at T&D Asset Management.

The pharmaceutical sector outperformed, with the sub-index up more than 2%.

Big pharma firms Chugai Pharmaceutical and Daiichi Sankyo Co Ltd were up 4.41% and 3.42%, respectively.

Shares of technology-related companies retreated from recent highs, with Screen Holdings Co Ltd down 2.59%, followed by Lasertec Corp losing 2.46%. Sony Group Corp was down 2.33%.

(Reporting by Brigid Riley; Editing by Subhranshu Sahu and Sherry Jacob-Phillips)