After Friday afternoon's surge on the back of better than expected US jobless data investors looks set to be quick to bank profits at the start of the new week. City traders expect London's blue-chip index to open almost 30 points lower at around 5,947.Energy supplier Centrica expects profits growth in 2011 to be more subdued than previously anticipated due to the new tax regime on UK oil production. The increase in the Supplementary Charge (SCT) rate from 20% to 32% on UK production announced in March in the government's budget offsets the benefit of higher commodity prices on its production business, the group claimed.Outsourcing giant Serco is drawing comfort from its £29bn pipeline of identified opportunities despite some short-term headwinds in the UK, and is on course to hit its 2011 targets.Anglo-Dutch household goods giant Unilever has received regulatory clearance to acquire US personal care and household brands firm, Alberto Culver, after agreeing to divest the Alberto VO5 and Rave brands in the US.Casino and bingo hall operator Rank has advised its shareholders against accepting a 150p a share offer for the company, saying it "significantly undervalues Rank and its prospects."