Mist, a Holstein cow hailed as the probable matriarch of a dynasty of star milk producers, was bought Saturday by a group of investors for $1.3 million, the largest price ever paid for a cow at auction.

The figure was at least $100,000 above the price paid for the previous record holder, a Texas cow, said an auction spokesman, Kate McGrath.

The cow was bought by a group, Mist Syndicate, led by a Boston lawyer, Jerome Rappaport, who was Mist's sole owner before the auction.

Mr. Rappaport, who owns a farm in East Montpelier, said he put Mist up for auction ''to generate the concept of the value of the cow.''