June 26 (Reuters) - European shares opened lower on Friday, with technology shares tracking global sector weakness, while Zalando fell after Germany's financial regulator launched a probe into the retailer's accounts. The pan-European STOXX 600 index was down 0.46% at 637.27, as of 0711 GMT, retreating from a record-high close in the previous session. The benchmark, however, is on track for a weekly gain.