BANDAR SERI BEGAWAN, April 3 (Xinhua) -- Brunei's economy was estimated to have contracted by 1 percent last year despite a significant increase in domestic investment, according to a report by the Asian Development Bank released on Wednesday.

The Asian Development Outlook 2019 said the contraction of the sultanate's gross domestic product, a measure of a country's economy, reversed its 1.3 percent growth in 2017.

This was most likely due to a reduction in oil and gas output which accounts for 57.3 percent of the country's economy, said the report.

"Crude oil production fell by 1.5 percent while the production of natural gas and liquefied natural gas shrank by more than 3.0 percent each," it said.

"The rest of the economy contracted as well, by 0.8 percent, in the three quarters of 2018 for which data are available. On the demand side, lower exports and domestic consumption drove down GDP growth, more than offsetting a strong rise in domestic investment," it added.

The report said reduced oil and gas production also lowered the volume growth in exports of goods and services to less than 1 percent in the first three quarters of last year.

It added that domestic consumption contracted by 0.4 percent as the government consumption declined by 1.3 percent.

"Meanwhile, domestic investment rose by a whopping 23.1 percent, largely reflecting continued work on the Hengyi refinery, the Temburong Bridge, and a fertilizer plant for Brunei Fertilizer Industries," said the report.