UPDATE 4-TeliaSonera, Alfa to merge MegaFon, Turkcell stakes

* Telia and Alfa Group aim to end long-standing dispute

* To list new company in New York

* Agree to join forces in legal dispute with Cukurova

* Telia shares up 6 pct

(Adds new analyst, company comment, share price reaction)

By Simon Johnson and Helena Soderpalm

STOCKHOLM, Nov 12 (Reuters) - TeliaSonera (TLSN.ST) and Alfa Group said on Thursday they would combine their Eurasian mobile assets, a move that could help them resolve a bitter dispute over ownership of top Turkish operator Turkcell (TCELL.IS).

TeliaSonera, the Nordic region's biggest telecom operator, said on Thursday it had agreed with Russian oil-to-telecoms group Alfa to combine their holdings in mobile operators MegaFon in Russia and in Turkcell.

Telia has been sparring with unlisted Turkish conglomerate Cukurova since 2005 when the Turkish group backed away from a deal to sell shares in Turkcell to Telia, opting instead to form a venture with Alfa.