United Natural Foods climbs after BMO upgrades to 'outperform'

** Shares of grocery wholesaler United Natural Foods UNFI.N up about 3% at $30 premarket

** Brokerage BMO upgrades stock to "outperform" from "market perform"

** Cites co's success in executing its network optimization strategy and "better-than-expected" customer retention

** Also raises PT to street high of $36 from $25

** BMO believes the recent cyber breach is just a temporary setback and does not affect its core business momentum

** Four of 11 brokerages rate the stock "buy" or higher, 7 "hold"; their median PT is $29 - data compiled by LSEG

** Up to last close, UNFI stock up about 7% YTD