Kerry arrives in Geneva as Iran nuclear deal comes into sight

* Possible compromise on Iran's stated "right to enrich" uranium

* France's Fabius says in Geneva to reach "solid deal"

* China, British, French, German foreign ministers to join talks

* Iranian chief negotiator sees "considerable progress"

* Fate of Iran's Arak heavy-water reactor remains at issue

* Israel renews campaign of criticising offer to Iran (Adds Kerry's arrival in Geneva)

By Parisa Hafezi and John Irish

GENEVA, Nov 23 (Reuters) - U.S. Secretary of State John Kerry arrived in Geneva on Saturday to join talks on Iran's contested nuclear programme, as Tehran and six world powers appeared to be on the verge of a breakthrough in the decade-old dispute.

The Chinese, French, British and German foreign ministers - Wang Yi, Laurent Fabius, William Hague and Guido Westerwelle - were due along with Kerry to take part in intense negotiations on a deal under which Iran would curb its atomic activity in exchange for some relief from economic sanctions.

The announcements came after diplomats in the Swiss city said a major sticking point in the talks, which began on Wednesday, may have been overcome.

A senior European diplomat told reporters earlier that foreign ministers of the six states would come to Geneva only if there was a deal to sign. "We have made progress, including core issues," the diplomat said.

France's Foreign Minister, who spoke out against a draft deal floated at the November 7-9 negotiating round, appeared guarded on arrival in Geneva early on Saturday.

"I hope we can reach a deal, but a solid deal. I am here to work on that," he said.

France has consistently taken a tough line over Iran's nuclear programme, helping Paris forge closer ties with Tehran's foes in Israel and the Gulf.

However, a French diplomatic source urged caution.

"It's the home stretch, but previous negotiations have taught us to be prudent."

Russian Foreign Minister Sergei Lavrov arrived in Geneva on Friday evening and met Iranian Foreign Minister Mohammad Javad Zarif and EU foreign policy chief Catherine Ashton, a Russian spokeswoman said.

Kerry left for Geneva "with the goal of continuing to help narrow the differences and move closer to an agreement," State Department spokeswoman Jen Psaki said.

The decision was taken after consulting with Ashton, who is coordinating talks with Iran on behalf of the United States, Russia, China, France, Britain and Germany, Psaki said.

Later, deputy State Department spokeswoman Marie Harf said that Kerry decided to travel to Geneva "in light of the progress being made" and with "the hope that an agreement will be reached".