By Sergio Goncalves

LISBON, Oct 27 (Reuters) - Portugal's largest utility EDP EDP.LS said on Friday it had agreed to sell 50% of its unit Abono, which has two coal-fired power plants in northern Spain, and plans to convert one of the plants to be fired with gas until mid-2025 and close the other.

In a statement, EDP said the sale to privately-owned conglomerate Corporacion Masaveu, with which it has a partnership agreement, will be made for an enterprise value of 350 million euros ($370 million) and an equity value of 60 million euros for 100% of the asset.

Abono consists of two thermal groups - Abono I and Abono II - with a combined capacity of 904 megawatts (MW), near Gijón in the region of Asturias. The plant that will be converted from coal to gas is Abono II.

The company said it had also requested authorisation from the Spanish electricity system operator Red Eléctrica to close the Abono I, as well as EDP's last remaining coal-fired power plants in Spain - Soto 3 and Los Barrios.

EDP said it will maintain the management and development of transition projects taking place in Abono, "namely hydrogen and renewable energy projects".

EDP plans to be coal-free by the end of 2025 and use only renewable energy sources by 2030. Renewable capacity already accounts for 80% of EDP's total installed capacity and is its current main growth driver.

EDP said in March it would invest 25 billion euros ($26.4 billion) over four years to nearly double its renewable energy capacity to 33 gigawatts (GW) by 2026.

($1 = 0.9475 euros)

(Reporting by Sergio Goncalves; editing by David Evans)

((sergio.goncalves@thomsonreuters.com; +351213509204; Reuters Messaging: sergio.goncalves.reuters.com@reuters.net))