* News of rate check pushes yen away from 24-year low

* Authorities won't announce intervention plan - finance minister

* MOF will act 'swiftly without interruption' if it were to act

* Govt jawboning heightens attention on BOJ's Sept. 21-22 meeting

* BOJ seen maintaining ultra-low rates - sources (Adds latest quotes by finance minister)

By Kantaro Komiya, Leika Kihara and Tetsushi Kajimoto

TOKYO, Sept 14 (Reuters) - The Bank of Japan conducted a rate check with banks on Wednesday in apparent preparation to step in to tame sharp yen falls, providing what analysts said would only be a brief respite for the currency, given the low chance of actual yen-buying intervention.

The yen rose by more than 1% on news of the rate check, reported earlier by local media and confirmed by Reuters, in a sign of rising market nerves amid the currency's recent sharp declines. At 1036 GMT, the currency stood at 143.07 per dollar, well above a 24-year low near 145 per dollar hit last week.

Finance Minister Shunichi Suzuki said authorities would make no advance announcement of plans to intervene, and usually would not confirm they had stepped into the market after doing so.

"Yen moves have been quite rapid over the past few days," Suzuki told reporters. "If we were to step in, we will do so swiftly without any interruption."

News of the rate check underscores growing concern among policymakers over the yen's sharp pace of fall, which not only hurts consumption by inflating the cost of imported raw material but heightens uncertainty for firms in making business decisions.

But analysts said the move would give only brief support for the currency, as Tokyo would likely struggle to gain consent from G7 counterparts to actually conduct yen-buying intervention.

"Never say never. They have been stepping up the rhetoric lately. But I would be cautious about the inevitability of their intervening. Japan is a signatory to the G20 and they have got policies about not intervening," said Rob Carnell, head of ING's Asia-Pacific research.

The yen has depreciated nearly 30% this year, as the Bank of Japan (BOJ) has kept policy super-loose while many of its global peers, such as the U.S. Federal Reserve, have aggressively raised interest rates to combat surging inflation.

Data issued on Tuesday showing unexpectedly strong U.S. inflation for August prompted bets the Fed would keep hiking rates for longer, adding downward pressure on the yen.

A rate check by the BOJ, a practice in which central bank officials call up dealers and ask for the price of buying or selling yen, is seen in markets as a possible precursor to action.