BUZZ-TalkTalk: Exane downgrades on competition fears
** Phone and broadband provider TalkTalk falls 3.8 pct after Exane double-downgrades to "underperform" from "outperform"
** Broker says threat of competition from Sky (LSE: BSY.L - news) and Vodafone likely to see TalkTalk suffer
** Says co likely to just hit FY17 guidance but consensus is too optimistic
** Fourth top faller on FTSE 250 index