DUBAI (Reuters) - An international telecommunications treaty signed by 89 countries out of a possible 144 on Friday will have little impact on how carriers operate or how consumers surf the web or make calls around the world when it comes into effect in 2015.

But the acrimonious debate over the treaty - and refusal of so many countries, including the United States and much of Europe, to sign up immediately - have exposed a deep split in the international community.

A U.S.-led bloc advocated a hands-off approach to the Internet, while Russia, China and much of Africa and the Middle East sought greater governmental oversight of cyberspace.

About 150 nations met in Dubai, under the auspices of the International Telecommunication Union (ITU), to update a set of telecom rules dating back to 1988, before the Internet and mobile phones transformed communications. Their failure to find a consensus may herald a new fight over cyberspace.

"The world will still be around and countries will still cooperate along the lines they have done for decades," said Paul Budde, managing director of Sydney-based consultancy BuddeCom. "However, they have clearly drawn a line under how far they believe the ITU can go in relation to regulations that include the Internet."

As in a prior version, the International Telecom Regulations spell out guidelines on technical issues such as how carriers charge each other for incoming international phone calls, as well as taxation and accounting.

Countries that sign the treaty are supposed to be guided by its principles, although these have no force of law.

Users in countries that block certain content will still experience the same version of the Internet, while telecom operators will feel little impact because international call charges are decided via commercial contracts between them.

The new version added passages that became flash points: for example, four lines pushed by Russia and China on how governments should protect the security of networks.

The United States took a no-compromise position throughout negotiations, refusing to consider any references to the Internet in the treaty. Other countries instead agreed to restrict any explicit Internet provisions to a non-binding resolution that accompanies the treaty.

In the end, the debate over the Internet overshadowed all else at the summit, despite the ITU insisting that regulating cyberspace was not on the agenda.

As a result, some countries in Africa and the Middle East felt the controversy overshadowed important reforms, such as provisions to improve broadband access to landlocked and island nations, which may be weakened by fewer countries signing the treaty.

Other measures include a call for greater transparency in roaming charges, which the ITU hopes will end "bill shock", plus commitments to improve disabled access to telecom services and for governments to reduce telecom equipment waste.

A clause calling for countries to stop "unsolicited bulk electronic communications" - spam - drew the ire of the U.S. bloc, which said it could be interpreted by governments to block emails, an accusation the ITU vehemently denied.

"Whatever is in place now doesn't seem to be working and this treaty calls on governments - it's a dirty word for some, but somebody has to do it - to cooperate to see what we can do better in that area," said Richard Hill, chief counselor for International Telecommunication Union's Dubai summit.

These issues are more vital in developing countries, with other countries having already addressed them to a large extent, so richer nations had less incentive to sign the treaty.

"That's certainly the case, but it's no secret they're not signing for political reasons," added Hill.

After 12 days of rancorous, largely private negotiations, the bad feeling between the two opposing camps may take some time to ease. Delegates from the pro-treaty group accused the United States and Europe of reneging on a compromise agreement that fell apart on Thursday.

ITU officials on Friday gave an upbeat interpretation of the summit, predicting many of the countries that had yet to sign the treaty would do so once they have consulted with their respective legislatures. But the failed attempts by some member states to significantly extend the ITU's remit into the Internet have weakened the 147-year-old organization.

"The ITU won't become irrelevant but it tried to claim some of the Internet without having the mandate to do so," said a European delegate who declined to be identified. "It saw an opportunity, but both the triumph and the curse of the ITU is that it can't instigate anything, it depends on member states - some said let's expand the mandate and others said let's not."

(Additional reporting by Leila Abboud in Paris; Editing by Nick Zieminski)