Police have released an image of a man wanted over the attempted murder of a pensioner in Sydney’s west, following what investigators believe was a random attack.

A 45-year-old man, Corum Ash, is being sought by police after a 74-year-old Yennora man was assaulted during his early morning walk on Saturday.

WATCH THE VIDEO ABOVE: Man wanted over attempted murder of pensioner

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Investigators have issued an arrest warrant for Ash, who is now wanted for attempted murder.

He is described as being of Caucasian appearance, approximately 170-175cm tall and unshaven with a medium build with short black hair and black eyes.

Ash is known to use public transport and frequents areas around Carlingford and Fairfield.

The elderly victim remains in a critical condition, fighting for life with serious head injuries sustained during the alleged assault.

Police have urged anyone who sees Ash not to approach him, but to call triple-0 immediately.