A process to prepare a stable solution of a borozirconate complex is disclosed and use of the solution in oil field applications such as hydraulic fracturing and plugging of permeable zones. The process comprises contacting zirconium complex with a first alkanolamine, then glycerol and water, then with a solution of a boron compound and a second alkanolamine. The solution is particularly suitable for use in a cross-linking composition at temperatures of 275.degree. F. (135.degree. C.) and higher in the subterranean formation.