(ShareCast News) - Liberum revisited its stance on UK general retailers on Tuesday in light of the more uncertain outlook following the vote to leave the European Union.The brokerage said it was more cautious on the generalists, given their UK exposure and in many cases high exposure to US dollar inputs.On the other hand, it highlighted a preference for specialists who are relatively more defensive and those that still have margin upside, are generating a superior rate of return on capital employed and have strong balance sheets.Liberum's key 'buy' is Boohoo, which it likes for its positive outlook and strong international growth and Jimmy Choo for its brand and positive forex dynamics.Other key buys are B&M for its strong market position and high cash generation, and Hotel Chocolat thanks to its strong brand, market position and margin upsideThe brokerage upgraded Supergroup to 'buy' from 'hold' on valuation grounds, noting the stock is trading some 6% below its long-term average.It cut Card Factory to 'hold' from 'buy' saying the stock was up with events on valuation and highlighting FX headwinds pressure in outer years.Liberum downgraded its stance on discount retailer Poundland to 'sell' from 'hold'. It said the shares were underpinned by a potential bid but in the event this does not happen there is 40% downside risk.Finally, it double downgraded Pets at Home to 'sell' from 'buy' citing a more volatile top line and margin pressures."Reflecting on the prelims and Brexit risks, we believe near-term headwinds have strengthened. FY16 performance suggested that revenues may be more volatile than we had expected and margin expansion has likely been pushed further out."We still acknowledge the company's strong market shares, improving multi-channel offering and the longer-term growth opportunity in Services. However, we see further downside risk before the shares make any substantial gains." Petrofac's stock was on Tuesday upgraded from 'hold' to 'buy' and its target price raised from 775p to 850p by Canaccord Genuity.Canaccord said with shares down more than 11% over the past three months against a 10% increase in the sector, the oilfield services company was a risky but attractive value-for-money stock."There have been incremental negatives, most obviously the $100mn liquidated damages on the Laggan-Tormore project: but we believe that at the current valuation, that enough is in the price," said analyst Alex Brooks."Petrofac's strengths are easy to list: it has a different risk profile to the rest of the UK oil services sector, but its performance track record suggests that this is not necessarily worse, particularly if the ill-starred diversification efforts of the past cycle do not recur in future."Brooks said the valuation has reached a "compelling level" at less than 6x 2017 price to earnings ratio, excluding integrated energy services.However, he noted that a substantial risk included being named in an investigation by the HuffPo / The Age into a Monagesque company, Unaoil, that allegedly facilitated the bribery of public officials.The UK's Serious Fraud Office and the Monaco police have been investigating further, and Petrofac has appointed Freshfields and KPMG to conduct its own investigation.While Canaccord expects "uninspiring" first half results due to weak order intake, the second half is forecast to prick up with a significant number of potential new contracts including some major Middle Eastern awards.Brooks said the completion of Laggan-Tormore removes one negative, the FPF1 for the Stella project should achieve sailway imminently, and several of Petrofac's assets are likely to be sold or move closer to sale in the period. "All these are positive triggers." Whitbread shares slumped on Tuesday as Barclays downgraded the stock to 'underweight' from 'equalweight' and slashed the price target to 3,220p from 4,150p.The bank said that although the shares have suffered in the wake of the UK's vote to leave the European Union, there is further downside risk as it is one of the most negatively-affected leisure stocks due to its exposure to business investment. Still, Barclays said it continues to like much about the structural growth opportunities at Costa and Premier Inn.The bank cut its forecasts 11% by 2017 and said it assumes as de-rating to 13.5x price-to-earnings, versus 12x in 2011/12 during the last UK slowdown in revenue per available room.It now expects RevPar to be down 3.2% this year and 1.6% in 2017/18. Despite assuming £27m cost savings, the bank's new estimates are 6% and 10% below Thomson One consensus for this year and next.Barclays said its downside case is similar to 2008-9 at 2,700p. "Unlike 2008-9, we believe the structural growth story is less supportive today with Costa's UK net system growth running at 6.4% versus 21% in 2009 and we see risk that the group slows the hotel rollout since around 35% of openings are extensions."Nevertheless, the bank said short-term trading may not be too bad, with London likely to see more leisure tourism due to the weak pound. It noted that Kayak and Cheapflights had reported a surge in searches for trips to UK.Meanwhile over the summer, leisure travel in the UK regions could be supported by more staycations due to sterling weakness."We expect the real signs of corporate capex weakness to be more obvious from September."