(ShareCast News) - Pre-tax profits at newspaper publisher Trinity Mirror plunged to £12.1m from £50m in the first half of 2015 on the back of falling advertising revenues and payouts to victims of phone hacking. Revenues were down to £288.5m from £324m, while operating profits fell to £19.6m from £60m. Shareholders will get an interim dividend of 2p a share.Despite the profits slump, shares in the group were up 13.75p, or 10.3%, to 146.75p.The tough advertising environment has forced the group to double its cost savings target to £20m for the year. This will result in an increase in restructuring costs to £15m from £5m.The company, which publishes the Daily Mirror and Sunday Mirror, has set aside an extra £16m to cover phone hacking costs. It is also appealing against the scale of £1.2m costs awarded in May this year by Mr Justice Mann to eight victims of the scandal, including the actress Sadie Frost and former footballer Paul Gascoigne.Tight cost management led to underlying pre-tax profits falling 2.5% to £47m, mitigated by a £27m gain from Trinity's share of the weather information business MeteoGroup by the Press Association.Chief Executive Simon Fox said print advertising had been "more challenging than anticipated" during the period."As a result, whilst continuing to invest in people and technology to drive the ongoing growth in digital audience and revenue, we have taken further action to address our print cost base," he said."I remain confident that our strategy will deliver sustainable growth in revenue and profit over the medium term despite the difficult print advertising market conditions. The actions we are taking in support of both our print and digital products provide the Board with confidence that profits for 2015 will be in line with expectations."The company said July revenue trends "are better than those experienced during May and June, with total revenue falling by 11% representing an underlying decline of 9%"."Although monthly revenue trends are expected to remain volatile for the rest of the year the board continues to expect profits for the full year to be in line with expectations."