UBS lowers its earnings per share (EPS) forecast for South America-focused miner Antofagasta after the group reported lower-than-expected production figures on Wednesday.Group copper production reached just 129,800 tonnes in the first quarter, 22% below UBS's estimate of 166,500 tonnes, mainly as a result of the slower ramp up at the newly-commissioned Esperanza project in Chile's Antofagasta region.Consequently, the broker has downgraded its 2011 EPS estimate by 4.9%, but notes that there should be minimal changes going forward.The target price is lowered from 1,350p to 1,310p, and a 'neutral' stance is maintained.RBS trims its forecasts for business and technology service provider Logica as a result of the timing of cost savings, but keeps its positive stance on the stock after a "decent" set of first quarter numbers.While the outlook looks positive ("backed by reported 29% year-on-year growth in order intake in the first quarter of 2011 and a book-to-bill ratio of 143%"), RBS notes that a previously-announced £30m restructuring programme has seen delays, meaning that full-year cost savings will likely be at the bottom end of the company's guidance of £15-20m.The broker raises its full-year revenue forecasts to reflect first quarter strength but nudges down its operating profits estimates as a result of the later-than-expected cost savings programme. The target price is lowered to 155p, from 162p, but a 'buy' rating is still kept.Despite Peel Hunt raising Tarsus Group's target price by 20p, the broker downgrades the group from a 'buy' to 'hold', highlighting a limited upside to the share price.The international media firm - which specialises in exhibitions, conferences and online media - issued an interim management statement on Thursday which "points clearly to trading patterns in line with market expectation," said analyst Malcolm Morgan.Peel Hunt thinks that the appointment of Dan O'Brien as finance director (with significant mergers and acquisitions (M&A) experience) signals more emphasis on M&A activity, and this aspiration - "combined with increasing visibility on full-year numbers" - has prompted the broker to raise the target price to 175p, from 155p."However, the movement in the shares ahead of today's new suggests this leaves only 6% upside ahead of any corporate activity. We move to 'hold'," said Morgan.---BC