UPDATE 2-CEO of South Africa's troubled Eskom resigns

* Eskom chairman told employees CEO has quit-source

* New CEO to be appointed within 90 days

(Adds background, details)

By James Macharia

JOHANNESBURG, Nov 5 (Reuters) - South African state power firm Eskom's [ESCJ.UL] chief executive Jacob Maroga has resigned, a source close to the company said on Thursday.

Maroga's tenure has been marked by power shortages, a record loss of 9.7 billion rand ($1.25 billion) in the year to March and electricity price rises criticised for stoking inflation as South Africa battles recession. [ID:nLR677617]

The source said Eskom Chairman Bobby Godsell announced the resignation to Eskom staff earlier on Thursday.

An internal Eskom memo, released by the opposition Democratic Alliance, said the resignation was with immediate effect and the board was committed to replace Maroga within 90 days.

The board was considering who to appoint as acting CEO, the memo said. Sources within Eskom have suggested it could be Brian Dames, current head of the generation business.