MADRID, July 28 (Reuters) - Spain's second-largest oil

refiner Moeve, formerly known as Cepsa, said on Monday the

massive power blackout that hit Spain and Portugal cost it more

than 50 million euros ($58 million), and it was considering

legal action.

Adjusted net income dropped to 324 million euros ($378

million) during the first half of the year, while earnings

before interest, taxes, depreciation and amortisation fell 33%

from a year ago to 733 million.

Both figures exclude one-off revenues and losses such as

asset sales.

The cost of halting and restarting its two oil refineries

during and after the April 28 blackout dragged down core profit,

the company said. It can take one or two weeks for such plants

to be fully operational after shutdowns.

"We're considering possible legal action once responsibility

for the blackout has been determined," a company spokesperson

said.

Redeia-owned Spanish grid operator REE has traded

blame with power utilities for the blackout. A government report

pointed to REE's failure to calculate the correct mix of energy

as one of the factors hindering the grid's ability to cope with

a surge in voltage that led to the blackout.

Rival Repsol, which operates five refineries in Spain,

said the blackout and other smaller power-supply issues cost it

175 million euros in the second quarter.

The Moeve refineries also halted for scheduled maintenance

during the first six months of this year, which further reduced

utilisation ratios, while refining margins narrowed to $6 a

barrel in the first half from $9.20 a barrel in the same period

a year ago.

Owned by Abu Dhabi fund Mubadala and U.S.-based private

equity firm the Carlyle Group ( CG ), Moeve rebranded last year

to reflect its shift towards low-carbon businesses under an

8-billion-euro plan. It has sold 70% of its oil production

assets since 2022, including operations in Abu Dhabi and South

America.

($1 = 0.8597 euros)