O'ahu's million-dollar home market wasn't immune to the general slowdown of residential real estate sales on the island, according to a new report.

There were 537 previously owned single-family homes that sold for more than $1 million last year on O'ahu, down 16.5 percent from 643 a year earlier, according to the report by Prudential Locations LLC.

The drop compared with a 16 percent decline for the entire market, and 15.9 percent for homes with sale prices under $1 million.

Prudential said high-end homes did outperform the broader market in how much more time they took to sell. The average number of days million-dollar homes spent on the market before selling rose 27 percent last year, compared with a 68 percent rise for all single-family homes.

However, it typically took longer to sell high-end homes last year, about 50 to 150 days, compared with about 30 to 45 days for the less expensive homes.

Most million-dollar home sales last year were in Kahala with 50. The highest median price for a neighborhood was Diamond Head, where the median in the third quarter peaked at $6.4 million.

Most sales — 419 of the 537 — were for $1 million to $1.99 million. There were three sales for more than $10 million.

Prudential said there were 586 million-dollar homes available for sale as of Jan. 1, including 20 for more than $10 million.

Prudential, one of the state's leading residential real estate firms, calculates its sales data differently than O'ahu's industry trade association, Honolulu Board of Realtors, which reported single-family home sales were down 12.5 percent last year.

Reach Andrew Gomes at agomes@honoluluadvertiser.com.