The company said the special gain was from tax credits which it said should continue for several years.
The bank said the special gain in the latest period is mainly from a tax credit.
The 1988 figure excludes special one-time gains and tax benefits totaling $336 million.
Excluding special gains, the increase would have been 32 percent, the company said.
Net income fell 38.1 percent after factoring out a special gain in the year before.
Sony reported net income of 36.3 billion yen, or $313 million, down 69.8 percent from the previous year, in which there was a special gain.
Excluding special gains and charges, the company had a net loss of $357 million, or $2.26 a share.
The company also had special gains of $131 million in the third quarter last year.
Yet even without the special gain, profits would have increased 26 percent.
The 1987 figures exclude a special gain of $126 million from restructuring activities.