421 Park Drive (pictured above left) at the Alexandria Center for Life Science – Fenway. Image courtesy of Alexandria Real Estate Equities

Boston Children’s Hospital will acquire nearly half of a new Fenway life science complex being developed by Alexandria Real Estate Equities.

The 660,000-square-foot development is scheduled to break ground this year at 421 Park Drive. Children’s Hospital will pay $155 million for a 268,000-square-foot section of the new building’s 550,000-square-foot office-lab space, which will include a 50,000-square-foot Star Market as its retail tenant.

Completion of the 421 Park Drive building is scheduled for 2026, Alexandria announced.

The development is the third phase of a 2 million-square-foot redevelopment of the former Landmark Center property. In April 2022, Children’s Hospital leased 42,000 square feet at 201 Brookline Ave., a new 480,251-square-foot life science tower developed on a section of the nearly 9-acre property.

Alexandria paid $1.5 billion in 2021 for an ownership share of the property with Samuels & Assoc., including the Art Deco-style building that functioned as a Sears catalog warehouse from 1928 to 1988 before being converted into office and retail space.

The Star Market will relocate from 1400 Boylston St., where Samuels is seeking approval for a 553,000-square-foot life science building.