* Nikkei, Topix make second biggest fall so far this year
* Concerns about upcoming earnings season lead to broadselling
* Volatility index jumps after put buying
* Canon falls 4.0% on media report of likely profit warnings
* Animation-related firms hit after suspected arson atstudio
By Hideyuki Sano
TOKYO, July 18 (Reuters) - Japanese shares recorded theirbiggest one-day fall in nearly four months on Thursday as dismalexport data and weak U.S. corporate earnings raised freshworries about fallout from the Sino-U.S. trade war.
The Nikkei share average fell 1.97% to 21,046.24points, hitting a one-month low and marking its second biggestslide so far this year only after a 3% plunge on March 25.
The broader Topix fell 2.11% to a one-month closinglow of 1,534.27.
"The earnings of global manufacturers will be soft for now.Investors are on the sidelines and waiting to buy on dips onlyif the Nikkei falls below 21,000," said Takashi Hiroki, chiefstrategist at Monex Securities.
As the U.S. earnings season kicked off, weak results fromrailway transport company CSX Corp stoked concerns thatthe protracted trade standoff between the United States andChina could hurt the profits of U.S. companies.
The outlook is seen even bleaker in Japan as companiesstruggle with the U.S.-China tariff war amid deterioratingglobal conditions that have dragged on its exports.
Japan's June exports to China dropped more than 10% from ayear earlier, its sixth fall in the past seven months, tradedata showed on Thursday.
Ahead of Japanese earnings seasons that will start laterthis month, Canon fell 4.0% after the Nikkei businessdaily reported its operating profit was on track to sink 40%this year.
NOK Corp fell 6.4% after the manufacturer ofsealant products slashed its earnings outlook, cutting itsannual operating profit estimates by 34% on weak sales ofcar-related products in North America and China.
Nikkei's slide accelerated after a few major technicalsupport levels, including 25- and 50-day moving averages.
Some brokerages bought a large amount of Nikkei put optionswith strike price of 20,000 -- essentially bets that the Nikkeiwill fall below that level -- to cover their trade with clients,further weakening the mood.
As a result, the Nikkei volatility index, which hittwo-year low of 13.01 the previous day, jumped to 16.44, makingthe biggest jump in nearly four months.
A broad range of shares came under pressure, including bothcyclicals as well as defensive shares, with declinersoutnumbering advancers by 96 to 2 on the main board.
Some shares with link to animation-making industry were hitafter more than 10 people are feared dead in a suspected case ofarson at an animation studio in Kyoto.
Cinema company Toho fell 4.5% while Toei Animationdropped 3.2%. Entertainment firm Bandai Namcolost 3.2%.
Elsewhere, Akebono Brake Industry Co Ltd rose 7.8%after the troubled car parts maker said it expects to receiveinvestment from a corporate turnaround fund to help restructureits money-losing business.(Additional reporting by Tomo UetakeEditing by Jacqueline Wong & Kim Coghill)