An announcement could come as soon as Tuesday morning U.S. time, according to a tweet by Faber.
Jeffrey Sloan, the chief executive of Global Payments, will run the combined company worth roughly $40 billion, according to the sources. Shareholders of Total System Services will receive 48% of the merged firm, they said.
Both companies did not immediately respond to CNBC's request for comment.
CNBC reported last week that the Global Payments was nearing a deal to acquire Total System Services for about $20 billion.
The consolidation comes as established financial companies seek to compete with new technology players, like Square and PayPal, which offer technology-driven services. Last year, venture capital funding for payments and processing grew to a total $18.5 billion — an almost fivefold increase from a year earlier, according to PitchBook.
The deal between Global Payments and Total System Services would also mark the latest in a flurry of activity in the payment technology space. Financial technology provider Fiserv announced plans in January to buy payment processor First Data in a deal worth $22 billion. In March, fintech group Fidelity National Information Services announced plans to buy Worldpay for roughly $35 billion.