OSLO, Aug 20 (Reuters) - Oil and gas investments in Norway, Western Europe's top producer, will rise more this year and decline less in 2021 than predicted a few months ago, an industry survey by the statistics office (SSB) showed on Thursday.

Investments in the country's main economic sector are now projected at 184.6 billion Norwegian crowns ($20.7 billion) in 2020 compared to 180.3 billion seen in May, SSB said, an increase from 177.6 billion crowns in 2019.

Next year, investment is expected to decline to 148.6 billion crowns compared to the previous view of 145.6 billion crowns, the survey showed. ($1 = 8.9323 Norwegian crowns) (Reporting by Nerijus Adomaitis, editing by Terje Solsvik)