LONDON, Aug 24 (Reuters) - Roche Holding AG has agreed to buy U.S. biotech company InterMune Inc for $8.3 billion in cash, marking the latest multibillion-dollar deal in a consolidating pharmaceutical sector, Roche said on Sunday.

The Swiss drugmaker will pay $74.00 a share for InterMune, representing a premium of 38 percent to the closing price on Aug. 22.

(Reporting by Ben Hirschler, Editing by Angus MacSwan)