Blacksmith Software, Sona Technologies Lease 26K SF at Moinian’s 245 Fifth Avenue
By Mark Hallum October 28, 2026 3:33 pm
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The Moinian Group signed two new technology firms at one of its Midtown South buildings.
Blacksmith Software, which provides support services to users of coding platform GitHub, leased 14,000 square feet, the entire seventh floor, of 245 Fifth Avenue, while AI-driven human resources firm Sona Technologies took all of the 12,000-square-foot 19th floor, according to the landlord.
The Moinian Group did not immediately provide asking rents or the length of the leases, but the average asking rent in Midtown South was $71.43 per square foot in the third quarter of 2026, according to a report from Lee & Associates.
“245 Fifth Avenue continues to attract a diverse mix of businesses seeking high-quality office space in one of Manhattan’s most dynamic commercial neighborhoods,” Omar Sozkesen, vice president of commercial leasing for the Moinian Group, said in a statement. “These transactions reflect strong demand in the building and the strength of its location, flexible floor plates and distinctive character.”
Newmark’s Scott Klau, Erik Harris and Ben Klau represented Moinian Group in-house while AI-native brokerage firm Tandem Space negotiated on behalf of Blacksmith.
Evan Kleinberg and Lenny Kohlmayer of Cornelia Street Partners negotiated on behalf of Sona Technologies.
Tandem Space and Cornelia Street did not immediately respond to requests for comment.
245 Fifth Avenue sits at the corner of Fifth Avenue and East 28th Street, two blocks north of Madison Square Park. Other tenants in the building include WeWork, which signed a 55,000-square-foot lease in August 2025 — only its second lease deal since exiting Chapter 11 bankruptcy — as well as the Institute of Integrative Nutrition, which signed a 14,000-square-foot renewal in March 2025.
Mark Hallum can be reached at mhallum@commercialobserver.com.
