UPDATE 1-Nokia seeks 1,000 voluntary redundancies

* Severance packages to go to first 1,000 volunteers

* Aims to avoid compulsory layoffs

HELSINKI, Feb 24 (Reuters) - Finland's Nokia (NOK1V.HE) is offering severance packages to the first 1,000 employees who volunteer to leave the world's biggest cellphone maker, in a move to help avoid compulsory layoffs.

The global initiative is part of "previously announced plans to increase cost-efficiency and adapt to the challenging market environment," the company said in a statement on Tuesday.

Employees can apply for the package between March and May, Nokia said.

Nokia, which plans to slash annual costs at its key handset unit by more than 700 million euros ($897 million), has said it would continue efforts to cut operational expenses, looking at all areas and activities.

The firm, which had 128,000 employees at end-2008, also said it is encouraging its staff to take unpaid leave and sabbaticals this year. (Reporting by Sakari Suoninen; Editing by Dan Lalor, John Stonestreet)