That put it ahead of IWG, whose Spaces brand is more closely comparable to WeWork venues than the traditional serviced offices operated by its Regus unit. IWG is considering selling Spaces. A growing list of local operators are now battling WeWork and IWG for market share. Blackstone (NYSE: BX ) Group's The Office Group and Germany's Design Offices are at the front of the chasing pack. Each of the firms has about 80,000 square meters of flexible office space, according to Colliers.