BUZZ-Top of the Street: Gemalto, Flughafen Zuerich, Tesco, Tullow

A round-up of notable broker activity this morning from Europe's top-ranked* analysts:

** Five-star ranked HSBC analyst Antonin Baudry cuts Gemalto (Swiss: GMT.SW - news) to "hold" as timing of profit warning only 3 weeks after renewal of 2017 guidance highlights lack of visibility on growth and cost base; Kepler Cheuvreux, Natixis (LSE: 0IHK.L - news) and JPMorgan (LSE: JPIU.L - news) also cut by one notch to hold-equivalent

** Top ranked DZ Bank cuts Merck (LSE: 0O14.L - news) to "hold" to match lower valuation after yr in which co achieved guidance only at lower end and a 2017 operating profit expected at 2016 level

** Tesco (Frankfurt: 852647 - news) : DB raises to "hold" on belief that UK business can improve profitability from its current levels, even on stable volumes; expects co to beat consensus on UK margin at prelims (April 12)

** Hermes: Natixis cuts to "reduce" on limited 2017 visibility; says growth and margins are to decline slightly

** Flughafen Zuerich (LSE: 0QPA.L - news) : Kepler Cheuvreux cuts to "reduce" as risk mounts that largest carriers SWISS and Air Berlin (LSE: 0GPE.L - news) could shrink seat capacities; adds that stock has moved from a significant discount to a 25 pct premium over the course of 2 yrs to the sector which is considered "demanding"

** Tullow Oil (LSE: TLW.L - news) : 5-star rated RBC analyst Al Stanton cuts to "sector perform" as Tullow's rights issue draws out any share price recovery

** Fingerprint: UBS (LSE: 0QNR.L - news) says co has been mainly impacted by inventory correction in last 2 qtrs and expects share price to show some support in the short term; raises to "neutral"

** Next (Frankfurt: 779551 - news) : Investec (LSE: INVP.L - news) raises to "hold" as co's FY guidance remains unchanged after profit warning in Jan. and strong cash generation underpins valuation

(*Analyst rankings from Thomson Reuters StarMine. Scale is from 1-star to 5-star with 5 being best. Analysts ranked on earnings accuracy as well as relative performance of recommendations over trailing 12-month & 24-month periods)