A leading Hawaiian businessman and the mayor of Honolulu made it clear Tuesday they welcome legitimate Japanese real estate investments despite concerns about those investments.

First Hawaiian Bank Chairman J.D. Bellinger told reporters that most Japanese investments in the islands contribute to the economic growth of the region on a long-term basis.In addition, Honolulu Mayor Frank Fasi said he welcomes any foreign investment in Hawaii as long as it is legitimate and good for people of his state.

In 1987 alone, Japanese investment in Hawaiian real estate soared to a record $3.3 billion, making Hawaii the largest investment target for the Japanese. Hawaii was followed by California and New York, according to a study by Kenneth Leventhal and Co., a Honolulu accounting firm.

That spending has raised some concern on the island and led the state Legislature to consider some bills crimping investment.

But Mr. Bellinger, in Tokyo as the Hawaiian representative of the Japan- Hawaii Economic Council, said reports of rising concern by Hawaiians about foreign investment were being exaggerated.

He noted that the Legislature rejected a proposal by Mayor Fasi to impose heavy taxes on capital gains resulting from the sale of real estate.

Mr. Bellinger also predicted defeat for a bill before the Legislature by banning Hawaiians from selling their land to foreigners.

The legislation is designed to end skyrocketing housing and real estate costs in Hawaii by prohibiting sale of residential, agricultural or preservation land to aliens.

It does not cover commercial, resort or industrial properties.

Mayor Fasi and his supporters are contending that passage of the bill would halt investments by Japanese buyers who are encouraged by the decline in the value of the U.S. dollar against the yen.

In a speech to the Japan National Press Club, Mayor Fasi said the bill is intended only to control speculative purchases of Hawaiian property and real estate.

Whether it's from Japan or Hong Kong or Canada or Great Britain, all I care about it that the investment is legitimate, Mayor Fasi said. That it creates jobs for our people and that it improves Hawaii.

Mr. Bellinger also said speculative real estate investments by some Japanese developers are clearly against the interests of the residents of Hawaii and he finds it impossible to approve of these purchases.

One prominent Tokyo real estate executive, who spoke to the press on condition he remained unidentified, admitted that Japanese investors are attracted by top-quality bargains in the Hawaiian Islands and particularly in and around Honolulu.

He pointed out that real estate companies in Japan are now much more familiar with property values in the Hawaiian region than they were only a few years ago.

And, he agreed that too-heavy Japanese purchasing has been driving up prices to everyone's long-term detriment.

Unfortunately, we Japanese have been buying up the choicest real estate parcels in and about Honolulu, not to mention other attractive parts of the islands as well, the developer said. My guess is that as much as $1 billion has been poured into the islands by Japanese investors in land and houses alone since the beginning of 1987 or thereabouts.

The main problem, or at least the most obvious one, is that Japanese buyers are willing to pay something like 30 percent to 50 percent more than the market value of the Hawaiian residential properties they want.

This is especially true of houses and condominiums in the Waikiki and Waialae-Kohala sections of Honolulu.