UPDATE 1-Alfa says better results needed to spin off Alpek unit

(Adds Alfa's stake in Alpek in paragraph 1, share price in paragraph 2; CFO comments, background after paragraph 3)

MEXICO CITY, Oct 24 (Reuters) - Mexican conglomerate Alfa will only spin off its 82%-owned petrochemical subsidiary Alpek when the financial results of Alpek and food unit Sigma improve to an appropriate level, company executives said on Tuesday.

Alpek has its own shares that trade publicly, but its results remain consolidated into Alfa's structure. The stock closed nearly 10% lower.

Alfa reported after markets closed on Monday that it swung to a loss in the third quarter, dragged down by Alpek's poor performance. Sigma, however, posted record revenues.

The conglomerate is aiming to spin off Alpek into a new listed entity, as it previously did with its telecommunications unit Axtel and auto parts maker Nemak.

Alpek's revenue was down about a third and its comparable core earnings dipped more than 60% year-on-year during the quarter.

The conglomerate needs to reduce its debt to proceed with its spin-off plans, and will consider selling non-core assets, Alfa's Chief Financial Officer Eduardo Escalante told analysts on a call to discuss third-quarter results.

Alfa's debt totaled $4.87 billion at the end of the third quarter.

Escalante hopes to see appropriate conditions for Alpek's spin-off soon, he said. "We are committed to continue with our transformation plans." (Reporting by Valentine Hilaire; Editing by Richard Chang)