Deals of the day — Mergers and acquisitions

(Updates: Starbucks; Adds: Porta, Bumble, Monte dei Paschi di Siena) Oct 12 (Reuters) — The following bids, mergers, acquisitions and disposals were reported by 2100 GMT on Monday: * Starbucks is not buying Chipotle Mexican Grill, the coffee chain said on Monday, quashing talk of a deal that could have been the largest-ever involving restaurants but was doubted by both investors and analysts.... * Medical equipment maker Steris will buy privately held Xodus Medical for $2.1 billion, adding surgical products designed to improve safety for patients and operating-room staff to its healthcare consumables business.... * Quantum computing company IonQ said on Monday it would buy cybersecurity firm Elisity in an all-stock deal valued at up to $1.3 billion, as it looks to expand its quantum security business.... * Bumble is in advanced talks to be taken private by Ithaca Holdings in a deal valuing the dating app operator at roughly $1 billion, a source familiar with the matter told Reuters on Monday.... * EU antitrust investigators opened an investigation into XXXLutz's proposed acquisition of German peer Porta on Monday, saying the deal may significantly affect competition in several EU c