Thailand's headline inflation cooled to its lowest rate in 15 months in March and came in below expectations due to lower energy and food prices, with the trend likely to continue this year, the commerce ministry said on Wednesday.

The headline consumer price index (CPI) rose 2.83% in March from a year earlier, compared with a forecast rise of 3.30% in a Reuters poll, and against February's 3.79% increase.

The core CPI index was up 1.75% in March from a year ago, the slowest pace in 14 months and under a forecast increase of 1.82%.

Headline inflation returned to the central bank's target range of 1% to 3% for the first time in 15 months, and the commerce ministry expects it to remain within the range for the rest of this year.

Last week, the central bank raised its policy rate for a fifth straight meeting and said its policy tightening would continue since, while inflation was slowing, it remained higher than in the past.

The central bank has hiked the benchmark interest rate by a total of 125 basis points since August to 1.75% to contain price pressures.

The commerce ministry forecast headline inflation would fall further later this year, helped by lower oil prices, government support measures and a high base last year, senior ministry official Wichanun Niwatjinda told a news conference.

Inflation in April, however, might not fall much because of spending ahead of a general election on May 14, he said.

"But inflation will definitely be lower than 2.5% from May," he said, adding it would be around 1% to 1.5% from June.

The ministry now predicts headline inflation to be 1.7% to 2.7% this year, down from a previous forecast of 2% to 3%, the ministry said.

In January-March, headline inflation was 3.88%, with the core rate at 2.24%. (Reporting by Orathai Sriring, Kitiphong Thaichareon and Satawasin Staporncharnchai; Editing by Martin Petty, Ed Davies)