UPDATE 2-Hynix seen a 'hard sell' as sole bidder pulls out

* Hynix shareholders to re-start sale process - KEB

* Hyosung walks away; shares jump 15 pct

* Hynix size, cyclical business are hurdles for sale

* KEB seeks local buyer; Hynix R&D seen as 'strategic'

* Sale may clash with other state assets on the block (Adds comment, analysis, updates shares)

By Marie-France Han and Rhee So-eui

SEOUL, Nov 12 (Reuters) - Leading shareholders of South Korea's Hynix Semiconductor (000660.KS) will restart the sale of a controlling stake in the world's No.2 memory chip maker, valued at close to $3 billion, after the sole bidder pulled out.

Failure to find an owner could leave major shareholders with little option but to sell Hynix shares on the market, as they have in small parcels in the past, inevitably denting its share price.

Hyosung (004800.KS), a mid-tier conglomerate with no experience in the memory chip business, said on Thursday it was withdrawing from the process, claiming market rumour and a misunderstanding of its intentions had made a fair acquisition process impossible.