As 2015 comes to a close, here are some of the top business stories of the year:

The Trans-Pacific Partnership (TPP) created the world's largest free-trade zone among 12 nations around the Pacific.

Together, they account for $28.5 trillion in combined gross domestic product, or 40 percent of the world's economic output. The TPP spans four continents and 800 million people. The agreement aims to strengthen economic ties, cut tariffs and foster trade among the member countries.

The 12 nations involved are the U.S., Japan, Malaysia, Vietnam, Singapore, Brunei, Australia, New Zealand, Canada, Mexico, Chile and Peru.

The TPP is a counterweight to China's growing economic power globally.

This year, the International Monetary Fund (IMF) selected China's yuan to be in the group of top global currencies. Experts said this showed a declining role for Europe in global financial markets, and an increasing role for China. It is the world's second-largest economy.

China had an economic slowdown in the third quarter, but analysts disagreed over its scope. There is a lack of transparency in the economic data that China provides to the rest of the world.

China also set up the Asian Infrastructure Investment Bank (AIIB). It is an international development bank with 57 countries participating. China will use the new bank to expand its global influence in Asia and compete with the World Bank in Washington, D.C.

Greek bailout

The huge bailout of the Greek economy was another big story this year. The International Monetary Fund (IMF), the European Commission (EC) and the European Central Bank (ECB) issued $97.6 billion to avoid a Greek bankruptcy.

It was feared that if Greece failed to pay its debt and left the Eurozone, it would cause a global financial crisis. In exchange for the bailout, the lenders demanded major economic reforms from Greece. Despite these measures, the Greek economy has shrunk by a quarter in five years, and unemployment is above 25 percent.

Volkswagen admits to lying

Volkswagen, Europe's largest automaker, was hit by scandal. The German automaker admitted to lying about carbon dioxide emissions from its cars. VW installed software that fooled regulators into thinking the cars emitted less pollution than they did.

The cars gave off up to nine times more pollution than the amount allowed by the U.S. government. In September, Volkswagen admitted that up to 11 million cars globally could have the misleading devices. Bringing all these vehicles into compliance with pollution regulations will be one of the most complex and costly fixes in automotive history.

U.S. Fed raises interest rate

Lastly, in the face of an improving economy, the U.S. Federal Reserve raised the key interest rate for the first time in seven years. The rate increase was just ¼ of a point. During the financial crisis of 2007 and 2008, the Federal Reserve cut the key interest rate to almost zero for the past seven years.

This was done to flood the economy with cheap money and boost hiring. Since the start of the Great Recession, unemployment has fallen from 10 percent to 5 percent.

And those are some of the top business and economic stories from 2015.

I'm Mary Gotschall.

Mary Gotschall reported on this story using a variety of sources for Learning English. Hai Do was the editor.