The New York Times Co.’s $ 1.1 billion purchase of the Boston Globe represents an expensive bet on the newspaper business.

The top executives of the two companies said at news conferences in Boston and New York on Friday that they hoped to lure advertisers targeting customers across the Northeast on the theory that two prestigious newspapers can jointly attract more business than they could separately.

Also, they plan to look at ways to save money by combining material purchases and the companies’ news and marketing databases.

Arthur Ochs Sulzberger, chairman/CEO of the New York Times, said the deal was a once-in a-lifetime opportunity he couldn’t pass up and that the papers were a “strong strategic and cultural fit.”

William O. Taylor, chairman/CEO of Globe parent Affiliated Publications Inc., said the deal “will preserve and enhance the long and proud tradition of the Globe.”

The Times agreed to pay what analysts said may be the highest price ever paid for a U.S. newspaper company.

Affiliated also owns 33% of BPI Communications, which owns Adweek, Billboard and the Hollywood Reporter among its 19 magazines.