American multinational private equity firm Blackstone Group LP (BX) is in advanced talks to purchase about 55 percent stake in the Financial and Risk Business of Thomson Reuters Corp (TRI) for over $17 billion, sources familiar with the matter said.

The financial media said on Monday that “it is in advanced discussions with Blackstone regarding a potential partnership in its F&R business.”

Thomson Reuters’ board will be meeting on Tuesday to discuss Blackstone’s all-cash offer for F&R business, the unit that supplies news, data, and analytics to banks and investment firms across the world. F$R unit contributed more than half of Thomson Reuters’ annual revenues.

According to experts, if the deal goes through, it would represent the largest shake-up of Thomson Reuters since the company was formed more than 10 years ago by Thomson Corp’s acquisition of Reuters Group Plc. Canada’s Thomson purchased London-based Reuters for 8.7 billion in 2008.