Selling six warehouse, office and retail properties on the mainland produced a whopping profit for local real estate investment and development firm Alexander & Baldwin Inc. in the first quarter.

The Honolulu-based company today reported earning $47.4 million in the first three months of this year compared with $7 million in the same period last year.

Most of the recent income was from selling six commercial real estate complexes on the mainland, which A&B said were sold for $159.2 million. Those sales combined with a few other property sales in the first quarter generated a $49.6 million gain.

A&B’s core commercial real estate business also includes operating a collection of mainly retail, industrial and office properties in Hawaii through which the company earns rental income from tenants. This segment of A&B’s business generated a $15.5 million operating profit in the first quarter, up 8 percent from $14.3 million a year earlier.

Two other main divisions of A&B offset year-over-year gains.

A “land operations” division generated a $5.4 million operating loss in the first quarter, which was worse than a $2.4 million operating loss a year earlier. And the road construction and materials business of subsidiary Grace Pacific generated a $200,000 operating profit in the first quarter, down from $5.6 million a year earlier.