Atlanta-based developer Jamestown LP has sold 245 First St., an East Cambridge office and lab complex, for $311.3 million to Clarion Partners.

Jamestown acquired the 260,000-square-foot two-building property in December 2013 for $192.6 million.

The property, previously known as Riverview and the Cambridge Science Center, contains 260,000 square feet of office and lab space in two buildings. A 10-story office building and 334-space parking garage were built in 1985 and a 6-story building built in 1900 for the Carter’s Ink Co. was later converted into labs. A 7,500-square-foot atrium connects the two structures.

Tenants include Massachusetts Institute of Technology, Akebia Therapeutics and the nonprofit oral health researchers Forsyth Institute.

Eastdil Secured represented the seller.

Cambridge office and lab rents continue to shoot up amid strong demand from tech and life science companies and historically low vacancy rates.

Average rents for Kendall Square office space hit $82 per square foot for class A space and $75 for class B space with an overall vacancy rate of 1.5 percent, according to Cresa Boston research. The lab market is even tighter, with a 0.3 percent vacancy rate and rents of $75 per foot for class A properties and $70 for class B.

Jamestown’s local properties include the Davenport office building at 25 First St. in Cambridge which is occupied by Hubspot, the Innovation and Design Building in Boston’s Raymond L. Flynn Marine Park, which it leases from the Boston Redevelopment Authority, and the Newbury Collection, a 219,000-square-foot mixed-use portfolio of 28 properties in Back Bay.

Clarion’s recent dispositions include 535-545 Boylston St. in Back Bay, which it sold in August to John Hancock Life Insurance Co. for $100.5 million, and a six-building, 407,458-square-foot office portfolio in Fort Point that it sold for $225 million to TIAA-CREF.