Sept 26 (Reuters) - U.S. credit reporting firm Equifax Inc said on Tuesday its Chief Executive Richard Smith will retire, a week before he was expected to testify before a Senate Banking Committee in the wake of a massive cyber attack.

Equifax disclosed earlier this month that personal details of up to 143 million U.S. consumers were accessed by hackers between mid-May and July, in one of the largest data breaches in the United States.

"At this critical juncture, I believe it is in the best interests of the company to have new leadership to move the company forward," Smith said. (Reporting by Supantha Mukherjee in Bengaluru; Editing by Sai Sachin Ravikumar)