Israel has acquired the user name @israel on Twitter, the microblogging Internet service, from the Spanish owner of a pornographic Web site, in an unusual transaction intended to help Israel exercise more influence over its image.

The owner of the user name, Israel Meléndez, got it in 2007, when Twitter was in its infancy. He struggled to use his account, however, because every posting prompted a flood of anti-Semitic or anti-Israel comments from Twitter users, in a case of mistaken identity.

“My account was basically unused because I was getting dozens of replies every day from people who thought the account belonged to the state of Israel,” Mr. Meléndez said.

Yigal Palmor, a spokesman for the Israeli Foreign Ministry, confirmed the purchase. He declined to say how much Israel paid, but he said that “it was not pro bono.”

“We thought we could put it to better use than he did,” Mr. Palmor said, adding that the purchase was in line with Israel’s recent efforts to expand into social media.

Mr. Meléndez, who is Spanish but lives in Miami, said that an agreement had been reached last month in a telephone negotiation that he conducted from the Israeli consulate in Miami. Mr. Meléndez described the sale price as “adequate.”

Israel then took over his Twitter account after first closing down the original version.

The transaction was first reported this month in Público, a Spanish newspaper.

Israel has been busy lately trying to improve its global image. Among other things, it added a military channel on YouTube, and it used the channel to defend an assault by Israeli Navy commando troops on a Gaza-bound aid flotilla in May.