Sept 9 (Reuters) - Warren Buffett's Berkshire Hathaway Inc said it has purchased another 3.5 million shares of Phillips 66, bringing its total stake in the U.S. refiner to 11.4 percent.

The latest series of purchase, made from Sept. 4-9, brings Berkshire's beneficially owned shares to a total of 61.5 million, according to a regulatory filing. (http://1.usa.gov/1UI6Bsn)

Berkshire's stake in the company is now worth $4.96 billion, based on Phillips 66's Wednesday closing price of $80.65.

Last month, Buffet reported a passive stake of 10.8 percent, or 58 million shares, as of Aug 25. (http://1.usa.gov/1UI6zAU) (Reporting by Ankush Sharma in Bengaluru; Editing by Leslie Adler)