Facebook hired Deutsche Bank, Credit Suisse Group and Citigroup to work on its $5 billion initial public offering and boost its credit, said a person with direct knowledge of the situation.

Facebook’s new and existing banks will grant the company a new credit line of more than $2.5 billion, said the person, who declined to be identified. Morgan Stanley, JPMorgan Chase, Goldman Sachs Group, Bank of America, Barclays and Allen & Co. were the first banks hired on the IPO.

The move would give the social network, where sales almost doubled to $3.71 billion last year, a pipeline of more than $5 billion in possible borrowings.

Facebook, led by co-founder Mark Zuckerberg, filed for the IPO last month and is pursuing what may be the largest Internet offering on record.

The expanded credit line will help Facebook pay taxes and the potential legal costs of patent litigation.