Mayor Bloomberg, who has crisscrossed the nation talking up his nonpartisan policy-making, is now exporting his independent politics to other countries.

Those who follow British politics say his planned appearance September 30 at a Conservative Party conference in Blackpool, England, could help the party establish itself as a more centrist alternative at a crucial time.

Mr. Bloomberg adds a marquee name to the roster of speakers attending the conference after Governor Schwarzenegger pulled out because of a possible special session of the California Legislature. The governor is now scheduled to address the group via satellite.

Mr. Schwarzenegger — who has called the mayor his “soul mate” and appeared with him on the cover of Time magazine — has joined forces with Mr. Bloomberg and others in an effort to create a credible and independent voice to counter the mainstream policies of the Democratic and Republican parties.

The mayor’s Blackpool speech, which will focus on the economy, comes as the leader of the Conservative Party, David Cameron, is attempting to rebrand the party after more than 10 years of Labour rule and build enough support to buoy the Tories back into power.

Mr. Bloomberg will appear at the conference about a week and a half after Mayor Giuliani will travel to London to receive the Medal of Freedom award from a former Tory prime minister, Margaret Thatcher, who has been butting heads with Mr. Cameron about the direction the Conservative Party is taking.

For Mr. Giuliani, who is seeking the Republican presidential nomination, the award offers important conservative credibility, as well as an international stage to discuss American foreign policy.

For Mr. Bloomberg, the trip is one more indication that, despite his declarations that he is not interested in running for president as an independent, he has no plans to put the brakes on his national and international travel.

It also highlights how much name recognition Mr. Bloomberg has in Britain, where he owns a home in London and where his company, Bloomberg LP, has offices.

In the past, both the Conservative and Labour Paty conferences have tapped big names in American politics to speak. Last year, President Clinton spoke at the Labour Party conference, while Senator McCain of Arizona spoke to the Conservatives.

“It’s both that he is a known international name and the Tories are aiming for competence,” a professor of government at the University of Nottingham, Philip Cowley, said yesterday, referring to Mr. Bloomberg’s invite.

Earlier this month, Mrs. Thatcher met with Prime Minister Brown pointedly dressed in bright red, the color of the Labour Party, an apparent slight to Mr. Cameron, whom she has criticized for moving away from the tenets of the Conservative Party she led, which were based in a free-market philosophy and tax cuts.

Inviting Mr. Bloomberg to speak is another sign that Mr. Cameron is more interested in expanding his party’s political tent, Mr. Cowley said.

“Some of this is about Cameron trying to move the party to the center. He doesn’t want people from the far right or the hard right popping up on his platform,” Mr. Cowley said during a telephone interview with The New York Sun.

A spokesman for Mr. Bloomberg, Stuart Loeser, said only that the mayor would discuss the economy. He did not say whether the mayor would address the fierce competition between London and New York over the financial services industry, or whether he would address climate change, on which both Mr. Bloomberg and Mr. Cameron have staked out major policies initiatives.

A Democratic political consultant, Daniel Gerstein, said the trip shows that Mr. Bloomberg has “established himself with a national leader,” regardless of whether he chooses to run for president.

A professor of politics at Strathclyde University in Glasgow, John Curtice, said Mr. Bloomberg does not have the same kind of name recognition in Britain as Mr. Schwarzenegger, who was an international bodybuilding champion and movie star before becoming governor.

Mr. Curtice said, however, that if relatively well known leaders in America such as Mr. Bloomberg are willing to speak to the Conservative Party, Mr. Cameron will have an easier time making the case that the party is worth listening to.