* Optimism about next earnings seasons supports market
* Altran skids more than 20 pct as U.S. forgery revealed
* Belgian telcos spooked by possible 4th operator
* Hays jumps 5 pct after strong results (Adds stocks, quotes)
By Julien Ponthus
LONDON, July 13 (Reuters) - European shares opened higher on Friday, and looked set for a second week of gains as fears of a full-blown trade war were kept in check and optimism about the next corporate earnings season grew.
The STOXX 600 was up 0.4 percent by 0824 GMT with a broad range of sectors, from industrials to technology and financials, adding points to the pan-European index.
Britain's FTSE led European bourses with a 0.7 percent rise as dollar-earning constituents were helped by a sliding pound after U.S. President Donald Trump criticised Theresa May's Brexit strategy, saying it had probably killed off hope of a U.S.-British trade deal.
"Unsurprisingly this was all too much for sterling to handle and cable dropped below 1.32 (dollars)," said Bart Hordijk, an analyst at Monex Europe.
Shares in French technology consultancy Altran Technologies tumbled more than 20 percent after the company said it had discovered a case of forged purchase orders within its recently acquired U.S. design and engineering services firm Aricent.
The forgery "relates to one individual, in his relation with one client" for an amount of $10 million, Altran said, adding that an investigation into Aricent's internal control procedures had been launched.
British recruitment company Hays was the best performer with a 5.1 percent rise after saying it expected full-year operating profit to exceed market expectations.
On the other hand, Switzerland's GAM Holding fell about 9.1 percent as it said it would take an impairment charge of around 59 million Swiss francs ($59 million) related to its 2016 acquisition of British hedge fund Cantab Capital Partners.
Still in the financial sector, shares in Norwegian insurance group Gjensidige fell 9.2 pct after its second-quarter results disappointed.
Belgian telecom companies also suffered as the government considers allowing a fourth mobile phone operator to enter the market.
Telenet, Proximus and Orange Belgium fell 5.2 percent, 2.9 percent and 1.2 percent respectively. ($1 = 1.0037 Swiss francs) (Writing by Julien Ponthus; Editing by Kevin Liffey and Susan Fenton)