Nokia Corp. said Tuesday it will lay off 1,700 people worldwide to cut costs, as the global economic downturn strikes deeper into the mobile phone sector. The world's top mobile phone maker said the job cuts will affect several sectors, including its devices and markets units, the corporate development office and global support functions. "The number of employees we have to reduce is 1,700," Nokia spokeswoman Arja Suominen said, adding that details would be announced after the company begins negotiations with employees. Nokia shares plunged 2.5 percent in Helsinki to â‚¬8.76 ($11.42) after the announcement, which came as the industry bellwether continues to struggle with falling demand and handset prices. In January, Nokia warned of major cost-cutting measures after its fourth-quarter net profit crashed 70 percent to â‚¬576 million ($744 million). It also lost market share, which fell to 37 percent from 38 percent in the previous quarter and 40 percent in the fourth quarter of 2007.