* Investors hunt for high-yield shares before ex-dividend day

* Market continues to focus on U.S. tax reform, econ stimulus

By Ayai Tomisawa

TOKYO, March 28 (Reuters) - Japan's Nikkei share average rebounded from more than a six-week low on Tuesday morning due to a pause in the yen's strong trend, with most sectors rose to positive territory.

With the end of the business year-end looming on March 31 for a majority of listed companies, the market was also underpinned by investor purchases of stocks before they go ex-dividend later in the day.

The Nikkei rose 1.0 percent to 19,177.10 in midmorning trade, after plumbing to its lowest level since Feb. 9 on the previous day as U.S. President Donald Trump's setback on his healthcare reform bill raised questions about his ability to push through his planned stimulus policies.

"Investors were overly risk off yesterday," said Hikaru Sato, a senior technical analyst at Daiwa Securities. "That said, for the next few weeks, the dollar-yen may still be volatile."

He added that the market continues to focus on developments on U.S. tax reform and infrastructure spending as well as political events in Europe such as the French presidential election next month.

Oil shares, drugmakers and trading firms outperformed helped by buying from investors hunting for high yields before the ex-dividend day.

Showa Shell Sekiyu surged 2.4 percent, Takeda Pharmaceutical rose 1.5 percent, Mitsubishi Corp advanced 1.5 percent and Mitsui & Co soared 1.0 percent.

Exporters gained ground after the dollar rose 0.1 percent to 110.800 yen following its slide to a four-month low of 110.110 overnight. Toyota Motor Corp gained 0.9 percent, Nissan Motor Co added 0.8 percent and Panasonic Corp jumped 2.9 percent.

The broader Topix gained 1.2 percent to 1,541.96 and the JPX-Nikkei Index 400 advanced 1.2 percent to 13,790.14.

(Editing by Simon Cameron-Moore)