A real estate firm is predicting that investors could spend around $1 billion less acquiring commercial property in Hawaii this year, which if accurate would be a third consecutive year of decline.

Commercial property brokerage firm Colliers International made the prediction in a report released last week, projecting that sales of property including hotels and retail centers likely will total between $3.1 billion and $3.3 billion this year, down from $4.1 billion last year.

If the Colliers forecast is on the mark, commercial property investing in Hawaii would be down 20 percent to 25 percent this year, and represent a third consecutive annual decline from a record $4.6 billion in 2014.

Colliers made its assessment largely on the expectation that there will not be more than a few additional “megadeals” this year because not much property priced over $100 million is available for sale. At the same time, the report said there is good demand, especially from smaller investors seeking properties for less than $5 million, that makes the overall market healthy.

“The outlook for Hawaii’s commercial investment real estate market remains upbeat,” the report said.

During the first half of this year, there were 156 sales statewide for a combined $1.9 billion, Colliers said in the report. That was more than the 125 sales for $1.1 billion in mid-2016, though the first half of last year had unusually lean activity that was followed by $3 billion in sales during the second half of last year.

Sales in the Colliers report include transactions over $1 million. Besides hotels and retail property, other types of commercial real estate are apartment buildings, industrial property, office buildings and undeveloped land zoned for commercial use. Golf courses are included in the resort, or hotel, category.

This year through June, the biggest transaction was the former Pacific Beach Hotel (now known as ‘Alohilani Resort) bought by Commerz Real AG, an investment firm based in Germany, for $515 million. The next biggest deal was the $317 million sale of the Westin Maui hotel to two U.S. investment firms, Trinity Investments LLC and Oaktree Capital.

Overall, there were seven resort/hotel sales for a combined $1 billion. The next biggest category was retail, with 33 transactions totaling $260 million. There were 38 land sales for $212 million, 29 industrial property sales for $192 million, 35 apartment building sales for $120 million and 14 office property sales for $114 million.

Hawaii buyers bought more properties — 114 compared with 42 for mainland and international buyers. But they spent less — $854 million compared with $1.05 billion for outside investors.

Colliers said 70 percent of all sales were for under $5 million, and that this activity by smaller investors helped produce a high midyear transaction total. That total, 156, was the highest midyear volume in more than a decade, though the full-year peak was 431 sales in 2005.