EBay (NASDAQ:EBAY)., owner of payments service PayPal, said it will bolster that business by buying Braintree for $800 million in cash, to expand its mobile transactions business.

Braintree’s online and mobile payments technology is used by popular startups such as vacation rentals site Airbnb, cab-hailing app Uber and restaurant reservations site OpenTable. The move comes as eBay’s PayPal unit works to evolve from its roots as an online payments provider, expanding its offline, mobile and online offerings to stores, restaurants and other business.

San Jose, Calif.-based eBay Inc. says that it will operate Braintree as a separate business. Bill Ready, the CEO of the Chicago-based company, will report to PayPal President David Marcus.

EBay says it expects to close the deal before the end of the year.  Braintree’s roughly 200 employees are staying with the company.

EBay, which acquired PayPal in 2002 for $1.18 billion, expects the unit to process $20 billion in mobile payments this year. The San Jose, California-based company said that PayPal contributed 40 percent of total revenue last year.

“Braintree is a perfect fit with PayPal,” Chief Executive Officer John Donahoe, said in a statement. The acquisition will add “complementary talent and technology that we believe will help accelerate PayPal’s global leadership in mobile payments.”

EBay was little changed at $54.10 at 8:20 a.m. in New York. The shares had gained 6.3 percent this year through yesterday.

(Bloomberg News and The Associated Press contributed to this report).