Japan upgrades Q4 GDP on robust capex, Iran war clouds outlook

* Q4 growth revised to 1.3% from 0.2%, beating expectations

* Energy disruption may cool consumption, investment, analyst says

* Japan's nominal GDP stands at $4.2 trillion, still larger than India (Adds analyst quotes, paragraphs 6, 9.)

By Kantaro Komiya

TOKYO, March 10 (Reuters) - Japan's economy grew faster than initially estimated in the final three months of 2025, thanks to rapid business investment, revised data showed on Tuesday, although the Middle East conflict casts a shadow over the growth outlook.

Gross domestic product (GDP) rose 1.3%, quicker than the paltry 0.2% preliminary estimate and slightly overshooting economists' median forecast for a 1.2% growth.

On a quarter-on-quarter basis without annualisation, GDP grew 0.3%, matching the median forecast for a 0.3% expansion and compared with the initial estimate of a 0.1% rise.

Businesses' capital expenditure rose 1.3% in the fourth quarter, the biggest growth since October-December 2023. It was revised up from the initial estimate for a 0.2% rise and beat the economists' forecast for a 1.1% uptick.

Private consumption, which accounts for more than half of Japan's economy, increased 0.3%, also upgraded from a 0.1% uptick in the preliminary data.

"The double upward revisions made it clearer that Japan's domestic demand-led economic growth is continuing," said Takeshi Minami, chief economist at Norinchukin Research Institute.

Domestic demand contributed 0.3 of a percentage point to fourth-quarter GDP, revised up from zero. External demand, or exports minus imports, was unchanged from the preliminary data of no contribution.

Other data released on Tuesday showed Japan's household spending unexpectedly fell 1.0% in January from a year earlier, boding ill for private consumption.

"Japan should continue to see growth through January-March, but after April, if energy imports remain disrupted due to the Iran conflict, higher prices could hit consumption and companies may also pull back on capital investment," Minami said.

To cushion the economic blow from rising fuel costs caused by the Iran conflict, Japan will consider steps to curb gasoline prices, Prime Minister Sanae Takaichi said on Monday.

The Bank of Japan has not shifted its tone on raising interest rates if the economy grows in line with its outlook, although governor Kazuo Ueda has said the potential hit to global growth from the Middle East conflict requires vigilance.

Japan's fourth-quarter growth followed a 2.6% contraction in July-September and a 2.4% expansion in April-June.

The size of the country's nominal GDP was 663.8 trillion yen ($4.20 trillion) last year after the revision, while India, seen close to overtaking Japan as the world's fourth-largest economy, was yet to cross the $4 trillion mark.

($1 = 157.9300 yen) (Reporting by Kantaro Komiya; Editing by Sam Holmes)