Ghana on Wednesday trimmed its estimate for economic growth last year to 4.0 percent, slightly lower than the 4.2 percent previously estimated, according to provisional data released by the national statistical service.

Unadjusted growth for the fourth quarter was 4.6 percent, compared to 4.9 percent in the same period of 2013, government statistician Philomena Nyarko told a news conference.

Nyarko said declining imports mainly accounted for the lower growth estimate for last year.

"The indications are that there were lower imports volumes in 2014 than earlier estimated. Marine fishing output also declined considerably," Nyarko said.

The West African nation started a three-year aid program worth $918 million with the International Monetary Fund this month in a bid to tackle its wide public deficit, growing public debt and high inflation.

The government forecasts that economic growth will slow to 3.9 percent this year due to the impact of lower commodity prices and a fiscal crisis that includes a high budget deficit.

Ghana enjoyed growth rates of around 8 percent for years on exports of gold, cocoa and oil, making it a magnet for investors who also liked its political stability.

Its economic reliance on commodities has made Ghana more vulnerable recently as global commodity prices fell.

Nyarko earlier announced that producer inflation slowed to 19.1 percent in March, from 21.8 percent the month before.