New concerns about the spread of COVID-19 variants slowed the US office market in August, but the availability of office space for sublease improved for the second straight month, allaying some experts' concerns about the near-term recovery for the sector.

A new report from CBRE tracking key indices of office market activity in 12 major US cities found that the sublease availability index fell in August after declining in July, though "sizeable" backlogs of space remain. Overall, Boston and Atlanta are registering the strongest comebacks, with the latter showing particularly strong gains last month. Los Angeles follows behind thanks largely to a slump in leasing last month. And in the next tier of markets CBRE analyzed for its report, Dallas-Fort Worth, Seattle, Washington, D.C., Manhattan and Houston have all shown modest improvement.

Nationally, the number of tenants in the market (TIM), defined as companies actively seeking office space, declined slightly after six straight months of gains, as did leasing activity as measured by finalized lease agreements. Overall, the decline nationally in tenants in the market is likely due to renewed caution by occupiers in the wake of an uptick in COVID-19 cases and the rise of the Delta variant, though some of that decrease can be attributed to the conversion of some tenants in the market to leases.