TOKYO, Aug 4 (Reuters) - Japanese shares slid the most

in almost four months on Monday, as concerns mounted over the

U.S. economy and a potential upheaval in domestic politics.

The Nikkei 225 Index of shares sank 1.8% and was set

for its steepest decline since April 11. The broader Topix

declined 1.5%, with a sub-index of bank stocks

plunging 4.2%.

U.S. shares fell sharply on Friday after data showed that

the world's largest economy created fewer jobs than expected in

July and a new round of punishing U.S. tariffs cast a shadow on

global trade.

On the home front, speculation grew that Prime Minister

Shigeru Ishiba might resign after last month's election defeat.

Ishiba has consistently denied plans to step down after his

ruling coalition lost its majority in the upper house of

parliament, but pressure from within his Liberal Democratic

Party is mounting.

"We had very weak job market data in the U.S. and sentiment

among investors has darkened," said Kenji Abe, chief strategist

at Daiwa Securities.

"There is some chance that Prime Minister Ishiba may be

forced to step down, so I think that's one thing we should

watch."

There were 34 advancers on the Nikkei against 189 decliners.

The biggest loser was Credit Saison ( CSASF ) with a drop of

8.2%, followed by Yamaha ( YAMCF ), which sank 7.9%.

The U.S. Labor Department said the country added 73,000

nonfarm payrolls last month, below economists' expectations,

while June's job growth was revised sharply lower.

Tariffs that U.S. President Donald Trump imposed last week

on dozens of countries are likely to stay in place rather than

be cut as part of continuing negotiations, Trade Representative

Jamieson Greer said.

The tariffs include a 35% duty on many goods from Canada,

50% for Brazil, 25% for India, 20% for Taiwan and 39% for

Switzerland.

Among the few gainers on the Nikkei, chip maker Socionext ( SOCNF )

rose the most, up 3.9%, followed by optics company Hoya

, which advanced 2.7%.

(Reporting by Rocky Swift in Tokyo; Editing by Subhranshu Sahu)