Mattel Inc. shares dropped 5 percent Monday after the El Segundo toy maker announced that Bryan Stockton resigned as chairman and chief executive, and that early estimates of recent quarterly sales and net income fell off sharply from last year.

Stockton will be replaced by longtime board member Christopher Sinclair, who will take over as chairman and chief executive effective immediately, the company said.

As it announced the C-suite shakeup, Mattel also released preliminary fourth quarter and full-year earnings. Net income was $150 million (44 cents a share), a 60 percent drop from last year’s fourth quarter net income of $369 million ($1.07 a share.) Sales of $1.99 billion for the quarter were down 6 percent from the same period last year.

For the full year, the company reported net income of $499 million ($1.45 a share), down 45 percent from 2013, when net income hit $904 million ($2.58 a share.) Sales slid 7 percent to $6 billion. Mattel said it will release final figures on Friday.

Sinclair, 64, said the board felt it was the right time for new leadership at Mattel to maximize its potential as it executes its strategic plan and revitalizes the business. The company will be seeking a new chief executive in the coming months, he added.

Mattel shares closed Monday at $26.64, down $1.40 or 5 percent. Over the past year, the company’s stock is down 38 percent as Mattel has continued to report declining sales.