UPDATE 2-Galapagos wins expanded Merck alliance, shares up

* Partnership value more than doubles to 400 mln euros

* Galapagos expects new alliances in oncology, asthma

* Shares up 4.2 pct (Adds more details, updates share price)

By Aaron Gray-Block

AMSTERDAM, Oct 14 (Reuters) - Belgian biotech Galapagos (GLPG.BR: Quote, Profile, Research)(GLPG.AS: Quote, Profile, Research) said it had expanded its alliance with Merck (MRK.N: Quote, Profile, Research) for the development of treatments for the hardening of arteries, doubling the potential value of the partnership.

Galapagos had entered into an alliance with Merck in January involving the development of treatments for diabetes and obesity, with milestone payments possibly exceeding 170 million euros ($253.1 million).

Wednesday's deal extends the cardiovascular alliance to include small molecule candidate drugs for pre-clinical development for the treatment of atherosclerosis -- or hardening of the arteries due to cholesterol build-up.

Galapagos is now eligible for milestone payments potentially exceeding 400 million euros, doubling the value of the alliance.

"Merck is becoming a very strategic partner for Galapagos," Chief Executive Onno van de Stolpe told reporters.