* Spain unveils draft cutbacks to renewable subsidies
* Wind power companies like Acciona hit hard
* Cutbacks look less painful for solar thermal firms (Adds details and impact for other energy firms)
By Tracy Rucinski
MADRID, Feb. 4 (Reuters) - Shares in Spanish renewable energy firm Acciona dropped on Tuesday, hit by draft proposals for cutting subsidies to the sector which analysts said were likely to hit the company's portfolio of mature, wind assets hard.
Shares in solar firm Abengoa, in contrast, gained on relief the proposals were not harsher for its business.
The Spanish government is cutting renewable energy subsidies as part of a drive to reduce a 30 billion euro ($41 billion) power tariff deficit, built up during years of keeping prices below regulated costs.
The draft rules, sent to affected companies on Monday, set the rate of return for existing renewable energy facilities at 7.4 percent and at 7.5 percent for future operations, versus over 10 percent previously.
But the new rules include variations according to over 1,000 different types of technology - including wind, thermosolar, photovoltaic and biomass - and the year the assets were installed.
For example, assets installed before 2004 will receive no subsidy and will only be awarded with the wholesale power price, while newer assets will receive the wholesale price plus a separate remuneration.
"The news is worse than expected, mainly for wind energy," Banco Sabadell said in a note to clients, adding that Acciona, with a large portfolio of mature wind assets, was likely to be one of the worst hit.
Analysts said the measures, which still need government approval, looked less painful for solar thermal assets, a technology in which Abengoa is a major player.
Shares in Acciona lost 5.0 percent to 46.645 euros by 1320 GMT, the biggest fall on Spain's blue chip index, while Abengoa gained 1.2 percent to 2.51 euros.
Overall, the draft proposals imply a cut in subsidies to the renewables sector of more than 1.5 billion euros.
The new rates are based on a review by two independent auditors and used Spain's 10-year government bond plus 300 basis points as a reference.
Companies have 20 days to give their feedback on the new rules, which have not yet been approved by the Spanish cabinet.
($1 = 0.7397 euros) (Editing by Mark Potter)