By Satoshi Sugiyama

TOKYO, June 8 (Reuters) – Japan’s economy lost momentum in the January-March quarter from the previous three months over sluggish capital expenditure, ‌revised gross domestic product (GDP) data showed on Monday, pointing to challenges ahead ‌due to the Middle East conflict.

The GDP figures released by the Cabinet Office showed the economy ​expanded an annualised 1.8% in the first quarter, compared with the initially estimated 2.1%. Economists’ median forecast was for 1.3% growth.

Without annualisation, GDP grew 0.5%, slightly better than the median forecast for a 0.3% expansion and matching the preliminary figure.

Private ‌consumption, which accounts for more ⁠than half of Japan’s economy, increased 0.3%, also matching the initial data.

Businesses’ capital expenditure shrank 0.7% in the first quarter, ⁠revised down from the initial estimate for a 0.3% rise and compared with an estimated 0.9% drop.

External demand, or exports minus imports, added 0.3 percentage point to GDP, ​unchanged ​from the preliminary data. Domestic demand contributed ​0.2 of a percentage point, also ‌matching the initial figure.

Japanese Prime Minister Sanae Takaichi’s government on Wednesday finalised a $19 billion supplementary budget for this fiscal year to cushion the impact of rising energy costs on households from the Middle East crisis.

U.S.-Israeli strikes on Iran in late February and Tehran’s effective closure of the Strait of Hormuz, which normally ‌carries a fifth of global oil and ​gas, have sent prices soaring and raised fears ​of a major disruption to ​energy flows.

Japan’s heavy reliance on Middle Eastern oil leaves it ‌acutely exposed. Rising fuel costs are stoking ​inflation, eroding household ​purchasing power and tightening corporate margins, heightening the risk of a severe economic downturn if disruptions persist.

The Bank of Japan will hold a two-day ​policy meeting next week. ‌Sources told Reuters the bank is expected to raise interest rates ​this month unless a sharp escalation in the conflict roils markets.

(Reporting ​by Satoshi Sugiyama; Editing by Sam Holmes)