* Turkey wary of Kurdish gains in Syrian civil war
* PYD leader expected to meet Turkish officials
* Visit comes as Syria-Turkey border tensions rise (Updates with more details and context)
By Humeyra Pamuk and Gulsen Solaker
ANKARA, July 26 (Reuters) - The head of a Syrian Kurdish group with links to militants in Turkey was in Istanbul on Friday for talks with government officials after an upsurge in fighting near the border, Kurdish political sources said.
Saleh Muslim, head of the Democratic Union Party (PYD), whose militias have seized control of districts in northern Syria over the past year, arrived in Turkey late on Thursday, the sources told Reuters.
Turkey is keen to extract assurances from the PYD that it will not seek to carry out actions on Turkish soil, will not try to carve out an autonomous region on the border, and that it will maintain a stance of firm opposition to Syrian President Bashar al-Assad.
Turkish government officials said there were no plans for any high-level meetings. Some local newspaper reports said Muslim would meet intelligence chief Hakan Fidan and Foreign Ministry officials.
Muslim said last week that the PYD aimed to set up what he said would be an independent council to run Kurdish regions in Syria until the civil war ended, a move likely to alarm Ankara, wary of an autonomous Kurdish region emerging on its border.
Turkey is trying to hold together a delicate peace process with Kurdistan Workers' Party (PKK) militants on its own soil and is worried that the emergence of an autonomous Kurdish region in Syria could further embolden them and jeopardise that process.
The PKK called a ceasefire this year as part of the efforts to end a three-decade conflict that has claimed 40,000 lives. But a recent increase in violence in the southeast has highlighted the fragility of the process. Kurdish politicians have voiced concern that the government has not been enacting promised reforms quickly enough.
The PYD captured the Syrian border town of Ras al-Ain last week after days of clashes with Islamist rebel fighters from the al-Qaeda linked Nusra Front.
Turkish troops shot at PYD fighters in Syria last week after two rocket-propelled grenades from Syria struck a border post on the Turkish side.
Two Turkish teenagers died when stray bullets from Syria hit the Turkish town of Ceylanpinar, adjacent to Ras al-Ain.
Clashes between PYD and rebels fighting Assad have erupted since Kurds began asserting control over parts of the northeast from late last year.
The anti-Assad revolt has evolved from its origins as a peaceful protest movement in March 2011 into a civil war that has killed over 100,000 people and turned markedly sectarian.
Turkey has emerged as one of the strongest backers of the Syrian rebels, giving them shelter on its soil, but denies arming them. Along with its allies, Ankara has, however, tried to distance itself from hardline Islamist groups like Nusra.
Syria's ethnic Kurdish minority has been alternately battling Assad's forces and the Islamist-dominated rebels. Kurds argue they support the revolt but rebels accuse them of making deals with the government in order to ensure their security and autonomy during the conflict. (Editing by Nick Tattersall and Robin Pomeroy)