May 7 (Reuters) - McKesson Corp reported weaker-than-expected quarterly revenue and profit on Tuesday due to slump in demand for the company's branded and specialty drugs that dragged sales in its U.S. pharmaceutical segment.

The drug distributor's pharmaceutical segment in the U.S., its largest unit by revenue that sells drugs used to treat complex conditions such as cancer, saw weaker-than-expected sales.

The segment also sells branded and generic drugs, as well as over-the-counter products and vaccines.

Sales in the segment rose 11.5% in the fourth quarter to $68.79 billion, but missed analysts' estimate of $71.65 billion, according to LSEG data.

The rise in sales in the reported quarter was helped by higher volumes from specialty products and partly by the demand for GLP-1 medications.

The Texas-headquartered company forecast 2025 adjusted per-share profit of $31.25 to $32.05, above analysts' average estimate of $31.02 per share, according to LSEG data. Shares of the company were down about 2% at $535 in aftermarket trading.

On an adjusted basis, McKesson posted per-share profit of $6.18 for the quarter ended March 31, versus analysts' estimate of $6.34 per share.

Overall, total revenue rose about 11% to $76.36 billion, below analysts' estimate of $79.32 billion. (Reporting by Pratik Jain in Bengaluru; Editing by Mohammed Safi Shamsi)