A Boston-based marketing company has signed on to lease nearly 160,000 square feet at an office tower steps to South Station.

Klaviyo will join Asics, Analog Devices and Haemonetics in the Oxford Properties Group-owned 125 Summer St., which contains 495,000 square feet of office space in Dewey Square. The lease represents a 135,000-square-foot increase in the size of Klaviyo’s headquarters, occupying the fifth through 11th floors.

Klaviyo will relocate from Oxford’s 225 Franklin St. property, where it leased 25,000 square feet in 2016. It operates under a software-as-a-service model providing email, web and mobile marketing.

In May, Klaviyo raised $150 million in series B funding from Summit Partners to hire hundreds of engineers and expand its corporate development team, primarily in Boston.