[New York Mayor Mike Bloomberg, Howard Rubenstein and Rupert Murdoch celebrate in New York last night. Photo via Amanda Gordon.]

Howard Rubenstein has had a lot of clients in his 56 years in the PR business. However, perhaps none have lasted as long as Rupert Murdoch, who first hired Rubenstein 37 years ago to handle the New York Post.

“We’ve become very, very close friends,” Rubenstein told PRNewser at last night’s launch event for The Wall Street Journal Greater New York edition. In fact, said Rubenstein, “he’s my closest friend in business.”

Asked about how business has been for his agency as of late, he said, “if you become good in more than one area, you can withstand the downturn,” citing a diverse client roster including education, real estate, sports, law firms and media companies. We’re still “well over 200 people,” he said, adding, “we keep fees within reason so we don’t lose clients.”

Like the seasoned PR executive that he is, Rubenstein declined to comment on The New York Times‘ war of words with the Journal, now that they’re both in direct competition. Asked if he’d ever done work for the Times, he said “I can’t,” due to his relationship with Murdoch and the competing New York Post.