* Nintendo scales 9-year high after broker raises rating

* Automakers, banks, brokerages outperform market

By Ayai Tomisawa

TOKYO, Sept 19 (Reuters) - Japan's Nikkei share average rose to 2-1/2 month highs on Tuesday as investor confidence was boosted by a weakening yen and strong U.S. shares, lifting cyclical stocks such as exporters and financial companies.

The Nikkei gained 1.5 percent to 20,197.56 points by the midday break, after hitting as high as 20,204.30 in early trade, its strongest level since June 29.

The broader Topix added 1.3 percent to hit a two-year high of 1,661.22.

Japanese markets were in part catching up to global equity gains and yen weakness after a public holiday on Monday.

The dollar was hovering around an eight-week high against the yen on Tuesday, but traders were cautious ahead of a two-day Federal Reserve policy meeting which starts later in the day.

Also helping risk appetite were hopes for a snap election.

Prime Minister Shinzo Abe is considering calling a poll for as early as next month to take advantage of his improved approval ratings and disarray in the main opposition party, according to government and ruling party sources.

"Investors were worried about 'Abexit' before, but if he calls a snap election and his ruling party wins, it would strengthen the foundations of his once-weak government base," said Hikaru Sato, a senior technical analyst at Daiwa Securities.

Abe's ratings had sunk below 30 percent in some surveys in July, battered by suspected cronyism scandals and a perception that he had grown arrogant after more than four years in office.

His popularity rebounded somewhat after a cabinet reshuffle in early August and has since been helped by worries over a volatile North Korea.

But Daiwa's Sato investors would be wary ahead of the Fed decision, which is not expected to produce a rate hike but could give clues on the pace of further policy tightening.

"It's not like they will chase the market higher from the current level until they see the outcome," he said.

All of the Topix's 33 subsectors were in positive territory, with financial stocks and exporters outperforming as risk appetite recovered.

Mitsubishi UFJ Financial Group soared 2.7 percent, Sumitomo Mitsui Financial Group climbed 2.1 percent, while Nomura Holdings advanced 2.6 percent.

Toyota Motor Corp surged 2.6 percent, Nissan Motor Co added 1.8 percent and Panasonic Corp gained 2.3 percent.

Nintendo Co surged 5.7 percent to hit a nine-year high after Credit Suisse hiked its stock rating to 'outperform' from 'neutral,' citing likely strong Switch sales. (Editing by Kim Coghill)