Pittsburgh Mayor Luke Ravenstahl said yesterday that he asked his ally, City Councilman Jim Motznik, to refrain from future Web blog attacks on City Councilman William Peduto, a mayoral challenger.

"I don't think it's productive, and I don't think it's in the best interests of the residents," the mayor said of Mr. Motznik's blogging. "We certainly have very important issues that we need to discuss, and the blogosphere is not, in my opinion, the best avenue to do that."

Mr. Motznik said he would honor the mayor's wishes. By yesterday evening, the blog could still be viewed, but had not been updated with new postings.

Mr. Motznik's first blog posting blamed Mr. Peduto for rumors surrounding the Oct. 31, 2005, handcuffing of Mr. Ravenstahl by police at Heinz Field.

Mr. Peduto has denied any role in the rumors.

"It would surprise me that Jim would do something this substantial without Luke's blessing," Mr. Peduto said. "Luke Ravenstahl and Jim Motznik are two peas in a pod."

The mayor said he knew nothing about Mr. Motznik's plans until after the blog went up.