* Mining sector top gainer, lifted by Inpex
* Volatility remains in market - analyst
* Japanese companies' annual profit forecasts flat - Daiwa
By Ayai Tomisawa
TOKYO, Feb 13 (Reuters) - Japan's Nikkei soared to a near two-month high on Wednesday as optimism there won't be a U.S. government shutdown and there will be a U.S.-China trade deal lifted risk appetites.
Oil explorer Inpex jumped 14 percent after sharply raising its net profit outlook for the year.
The Nikkei share average surged 1.5 percent to 21,185.59 at the midday break, after touching as 21,205.05, the highest level since Dec. 18.
The broader Topix gained 1.0 percent to 1,588.79.
The agreement in principle in Washington to avoid another shutdown helped boost Wall Street overnight.
Sentiment was also improved by hopes the United States would reach a trade deal with China. High-level trade talks in Beijing starting on Thursday will attempt to hammer out an agreement before a March 1 deadline for the U.S. to impose higher tariffs on $200 billion of Chinese goods.
"The same catalysts - developments surrounding the U.S. government shutdown and U.S.-China trade deals - have made the Japanese market volatile," said Takuya Takahashi, a strategist at Daiwa Securities.
"Investors are taking heart from the positive note from Wall Street yesterday, but volatility could persist depending on more headlines related to the events."
He also said the market has priced in Japanese quarterly earnings, with the season almost over.
According to Daiwa Securities, 152 out of 200 large companies that the brokerage covers, excluding SoftBank Group and other telecommunication firms, have reported a 1 percent drop pretax profits on average for April-December. For the fiscal year ending March, they expect their profits to be flat.
Wednesday's winners include index-heavy stocks such as SoftBank Group and Fanuc Corp soared, rising 6.1 percent and 3.5 percent, respectively.
Inpex hiked its full-year net profit forecast by 37 percent thanks to its Ichthys liquefied natural gas (LNG) project in Australia. Inpex was the board' biggest gainer and made the mining sector the top sectoral performer.
Kabu.com Securities rose 6 percent after KDDI Corp said on Tuesday it would spend $800 million to buy a minority stake in Kabu.com.
The broader Topix gained 1.1 percent to 1,589.45. (Editing by Richard Borsuk)