Jan 28 (Reuters) - Automatic Data Processing ADP.O lifted its annual revenue forecast on Wednesday and surpassed quarterly profit estimates, helped by steady demand for its payroll and human resources services.

ADP is one of the largest human resources management firms globally, and provides services ranging from administrative support to assistance on employee benefits.

The company reported revenue of $5.36 billion for the second quarter, beating analysts' average estimate of $5.34 billion, according to data compiled by LSEG. Adjusted profit per share came in at $2.62, compared with estimates of $2.57.

ADP now expects annual revenue to grow about 6%, at the top end of the previous forecast of 5% to 6% growth.

Its U.S. "pay-per-control" metric for the second quarter, which tracks how many employees are on its clients' payrolls, rose 1% from a year earlier, in line with the growth reported in the past three quarters.

Layoffs remain muted in the U.S. labor market, but hiring has slowed substantially.

(Reporting by Anhata Rooprai in Bengaluru; Editing by Sahal Muhammed)

((Anhata.Rooprai@thomsonreuters.com))