TORONTO — The world's largest gold mining company has announced plans to eliminate 100 jobs at its corporate headquarters in Toronto.

Barrick Gold Corp. said Monday the reduction represents 30 percent of the head office. Barrick spokesman Andy Lloyd cited a challenging business environment. Falling gold prices, rising costs and a sagging stock price weighed down by its Pascua-Lama project have plagued the company. Since late 2011, the gold price has fallen by $600 — over 30 percent.

Last month, Chile's environmental regulator stopped construction and imposed sanctions on Barrick's $8.5 billion Pascua-Lama gold mine, citing "serious violations" of its environmental permit. Barrick has already spent $5 billion on the project, which straddles the Chile-Argentine border at 6,400 feet (5,000 meters) above sea level. Barrick had hoped to begin production in early 2014, and warned shareholders that it might abandon Pascua's Chilean side if construction delays keep the mine from opening this year.

The company announced last week it planned to reduce its work force by 55 positions in Nevada and Utah. The company has some 4,500 employees in Nevada — which comprises the bulk of its North American operations — and 140 employees in Salt Lake City. Barrick has 25,000 employees worldwide.

Lloyd said impacted employees will receive severance packages and access to career placement services. The reduction follows a thorough review of the company's organizational structure that was prompted by the change in business conditions.

Barrick CEO Jamie Sokalsky promised shareholders in April that Barrick was committed to be focus on producing returns for investors. Shares of Barrick and almost every major gold miner have hit new annual lows recently.

Barrick ousted former CEO and President Aaron Regent a year ago, citing its disappointing share price performance. The stuck has plummeted from over $40 to less than $16 since then.

Shares dropped 94 cents, or 5.6 percent, to $15.95 in Monday morning trading on the New York Stock Exchange.