* Expects 2014 net profit at lower end of forecast
* 2015 net profit forecast well below estimates
* Shares fall nearly 25 pct to 4-yr low (Adds share movement, details)
Nov 24 (Reuters) - Oil and gas services firm Petrofac Ltd's net profit estimate for 2015 fell far short of its goal, wiping out more than 1 billion pounds ($1.56 billion) of its market value.
Petrofac's shares shed a fourth of their value in heavy trading Monday morning on the London Stock Exchange, falling to a four-year low of 898 pence.
The company, which builds and maintains oil and gas facilities and also invests in oil fields, said it was being hurt by delays and operational issues at several projects as well as falling oil prices.
The company said it expected about $500 million in net profit for 2015, far lower than its stated goal of $862 million and the average analyst estimate of $688.1 million.
Petrofac also said it expected 2014 net profit at the lower end of its forecast of $580 million to $600 million.
A trader at a large U.S. brokerage said lower oil prices should have been in analysts' projections but operational and execution issues raised were new and could prompt rating downgrades.
Petrofac had been aiming to double its 2010 net income by 2015 but turned cautious in November last year, when it warned of little or no growth in 2014.
Oil prices have been falling since the summer due to abundant supply - partly from U.S. shale oil - and weak demand in Europe and Asia.
Petrofac's profit warning reflects rising project costs at its Greater Stella development in the UK North Sea and production contract issues at its Ticleni project in Romania and with Petroleos Mexicanos in Mexico.
Petrofac had pinned its growth expectations on its Integrated Energy Services (IES) division, which invests in oil production with oil firms, but has instead faced project delays and production cuts. ($1 = 0.6395 pounds) (Reporting by Esha Vaish, Richa Naidu and Abhiram Nandakumar; Editing by Gopakumar Warrier and Saumyadeb Chakrabarty)