Bill Gates’s Firm Transferred $1.8 Billion in Stock to Melinda Gates Amid Divorce

An investment firm controlled by Bill Gates transferred stock worth more than $1.8 billion to Melinda Gates this week, when the billionaire philanthropists announced that they were ending their 27-year marriage.

The firm, Cascade Investment LLC, transferred to Ms. Gates more than 14 million shares of Canadian National Railway Co. , and more than 2.9 million shares of AutoNation Inc. on Monday, according to regulatory filings. As trading began Wednesday, the Canadian National Railway shares were worth about $1.53 billion, while the AutoNation shares were worth about $310.1 million.

The transfers come as one of the world’s wealthiest couples parts ways. The couple’s divorce petition filed Monday in King County Superior Court in Washington state indicated that they have a separation agreement under which they plan to divide their assets.

Cascade manages a large portion of the wealth that Mr. Gates amassed as co-founder and longtime leader of Microsoft Corp. Mr. Gates, who co-founded Microsoft in 1975, stepped down as its chief executive in 2000 and departed from his role as chairman in 2014. Cascade Investment didn’t immediately respond to a request for comment.

Despite their plans for divorce, Mr. Gates and Ms. Gates, who was born Melinda French, have said they would continue to work together at the Bill & Melinda Gates Foundation, which gives away billions annually as it aims to tackle global causes such as poverty and disease. Mr. Gates and Ms. Gates are both co-chairs and trustees of the foundation.