TOKYO, Oct 1 (Reuters) - Japanese shares tumbled on Friday to one-month lows on mounting fears various supply chain disruptions worldwide could keep inflation elevated for a much longer period.

Also weighing on investor mood was a delay in a vote on the Biden Administration's flagship spending bills, as Democratic leaders scrambled to assemble enough support.

The Nikkei average lost 2.31% to 28,771.07 while the broader Topix fell 2.16% to 1,986.31, both marking their biggest drop in three months to reach their lowest levels since early September.

"Worries that the U.S. infrastructure bill may not pass the Congress appear a main culprit today. But it's not like there was panic-selling," said Takeo Kamai, head of execution services at CLSA.

The Nikkei held above major support around 28,600-28,650, where its 50-day, 100-day and 200-day moving averages converge.

For the week, the Nikkei lost 4.89%, the biggest loss since the market crashed after the coronavirus outbreak in early 2020.

"Investors are starting to fear inflation is not temporary given various supply constraints. That means their economic scenario needs a major review," said a strategist at a Japanese brokerage who declined to be named as he is not authorised to speak to media.

Price pressure is rising globally due to staff shortages, lack of ships, soaring gas prices in Europe and power shortage in China.

Nitori lost 6.0% after the furniture store chain operator missed markets' top line forecast in its quarterly results.

Sumitomo Chemical fell 5.3% after its profit estimate for the quarter ended September fell short of market expectations.

Silicon wafer manufacturer Sumco lost 4.4% after it unveiled a plan to sell 128 billion yen ($1.14 billion) of new shares to fund an increase in silicon wafer production.

The shares that were added to the Nikkei average on Thursday dropped sharply in a reaction to gains prior to the inclusion.

Nintendo sank 8.7%, the biggest since early 2019, while Murata Manufacturing shed 5.7% and Keyence , Japan's second-biggest company by market capitalisation, fell 3.0%.

Bucking the trend, Toshiba gained 3.1% after activist U.S. hedge fund Elliott Management said it owns a "significant" stake in the Japanese industrial conglomerate.

Rakuten gained 3.2% after the e-commerce firm said it is preparing to list its online banking unit.

Gree jumped 16.2% to hit a limit-high after the game company announced a massive share buyback.

The market showed no reaction to the Bank of Japan's tankan business sentiment data. (Reporting by Hideyuki Sano; Editing by Sherry Jacob-Phillips and Subhranshu Sahu)