Monsanto Co. plans to slash another 1,000 jobs worldwide, bringing total planned cuts to 3,600, or about 16 percent of its global workforce, according to a filing Wednesday with the U.S. Securities and Exchange Commission. The job cuts are part of a broader, previously announced plan to target $500 million in annual savings by the end of fiscal year 2018.

The job cuts will vary from country to country, and are expected to continue through fiscal 2018, the company said.

The additional staffing cuts, along with site closures and contract terminations, are expected to increase a restructuring charge to a range of approximately $1.1 billion to $1.2 billion, from $850 million to $900 million, the company said.

Of that, $493 million occurred in the fourth quarter of fiscal year 2015 and $318 million in the first quarter of fiscal year 2016, the company said.

The remainder of the restructuring charge is expected in fiscal years 2016 through 2018, the company said.

The company's board of directors approved the plan, according to the filing.