Four leases totaling 17,536 square feet of office space at 100 Franklin St. and 141 Tremont St. have been completed in downtown Boston.

Energy efficiency technology company Cimetrics leased 10,946 square feet at 141 Tremont St., according to a statement. Ted Wheatley and Ben Heller of Jones Lang LaSalle represented Cimetrics.

The remaining three transactions took place at 100 Franklin St. Red Gate Real Estate Advisors leased 2,920 square feet; Davenport Investments leased 2,416 square feet; and airfare consolidator C&H International leased 1,254 square feet, according to a statement. The tenants were represented by David Martel of Cushman & Wakefield, Bonny Doorakin of NAI Hunneman and Brandon Leitner of Cressa Partners, respectively.

Jason Cameron, vice president, and Matthew Godoff, associate, both of Grubb & Ellis Co., represented the tenant, Synergy Investment & Development, in all lease transactions.

"We are very pleased to add these companies to our growing tenant roster and would like to thank the respective brokers and Grubb & Ellis for their assistance in helping us maintain a high level of occupancy throughout our portfolio," said Jim Grady, director of leasing for Synergy.

The 141 Tremont St. building is two stories and 68,645 square feet. The 100 Franklin St. building is nine stories and 120,240 square feet office.