Yahoo Japan Corp. said Monday its net profit for the three months ending in December jumped 37 percent to a record 12.65 billion yen, driven by strong growth in its advertising revenue.

Revenue at the Internet portal operator rose 51 percent to 46.62 billion yen, also a record. Yahoo Japan said it continued to see robust ad revenue growth, which jumped 72 percent compared with the same period the previous year, as more large businesses have begun to recognize the value of the Internet as an advertising medium.

Yahoo is one of several IT-related firms whose shares have been hit by the so-called Livedoor shock.

"It is very sad," CEO Masahiro Inoue said at a news conference when asked about the recent stock price fall triggered by prosecutors' investigation into Livedoor Co.'s suspected violations of securities exchange laws.

Inoue said he personally admires the bold attitude of Livedoor President Takafumi Horie. But he expressed dismay at being lumped together with Livedoor and other Internet-related firms, particularly those located in the Roppongi Hills complex in Tokyo.

For Horie and other Net startups, Yahoo Japan is a model they hope to follow and to topple someday.

"I have not been invited much to their gatherings nor shared (in their) tips," Inoue said, in reference to the circle of corporate executives of high-tech companies centered on Horie's Livedoor.

"I don't think it is proper to bundle (us) together just because we have offices in the same building."

Inoue said his company has set up a thorough process of approving mergers and acquisitions, stressing that it has a rigorous corporate governance and legal compliance regimen.