SAN JOSE, United States — Payment processor PayPal Holdings Inc. said on Wednesday it would buy privately held shopping and rewards platform Honey Science Corp. for about $4 billion.

The deal for the seven-year-old platform that finds and applies coupon codes on popular sites and helps consumers save money will add to PayPal's ability to help merchants deliver offers, PayPal said.

PayPal and its mobile payment service Venmo have more than 275 million active consumer accounts. The deal is expected to close in 2020 and would add to PayPal's adjusted profit in 2021.

After the deal, Honey will retain its headquarters and brand in Los Angeles, California, PayPal said in a statement.

PayPal shares were down 2 percent at $102 after the bell.

Perella Weinberg Partners LP was the financial adviser to PayPal, and Skadden, Arps, Slate, Meagher & Flom LLP was its legal adviser.

Qatalyst Partners was the financial adviser to Honey and Latham & Watkins, LLP its legal adviser.

By Abhishek Manikandan; editor: Arun Koyyur