Strip malls, which are usually anchored by grocery or drug stores, saw average vacancies spike 0.5 percentage points to 8.2 percent, a level unseen since 1995, according to the report released on Monday.
Vacancies at regional malls rose 0.4 percentage points to 6.3 percent, the highest level since the first quarter of 2002, according to the preliminary results.
"They definitely came up weaker than our expectations and we've been pretty bearish on our outlook for retail for some time," Reis Chief Economist Sam Chandan said. "In the market in general there have been a lot of store closings."
A growing list of retailers shuttered stores ahead of lease expirations or chose not to renew leases, and as newly completed space hit the market without signed tenants.
Starbucks recently said it would close 600 stores by March. GAP is looking to give up some of the 40 million square feet of retail space it leases. That's in addition to the growing list of retailers, such as Linen 'n Things and Goody's Family Clothing, which filed for bankruptcy protection.
For the first time since 1980, more space became available to rent at strip malls than was rented out -- about 3.2 million square feet more. Part of the available space came in the form of 5.7 million square feet of new development that came on the market during the quarter.