TOKYO (Reuters) -Japan's current account surplus more than doubled year-on-year in May, in a fourth straight month of gains, as the country's trade deficit narrowed and income gains from its overseas investment expanded, Ministry of Finance data showed on Monday.

The current account surplus reached 1.86 trillion yen ($13.08 billion) in May, compared with 773 billion yen in the same month a year earlier and just short of economists' median forecast for a surplus of 1.88 trillion yen in a Reuters poll.

A breakdown of the data showed the trade deficit narrowed to 1.2 trillion yen from 1.8 trillion yen in May 2022, a ministry official said.

The primary income surplus hit 3.6 trillion yen, up from 3.1 trillion yen in the same month a year earlier, resulting in an overall surplus for a fourth straight month.

Dividend payments from overseas business affiliates in sectors such as automobiles and interest payments from securities investments helped drive up income gains.

Over the past year, the current account data has highlighted the pain that high energy costs and a weak yen have inflicted on the world's third biggest economy, which relies heavily on imports of fuel and raw materials.

Japan's position as an export powerhouse has also waned in recent years, in part because companies have moved production overseas, making overseas investment a pillar of the country's earning power.

($1 = 142.2200 yen)

(Reporting by Tetsushi Kajimoto; Editing by Sonali Paul)