Abstract: This invention relates to compositions which can be stored under anhydrous conditions, but when exposed to atmospheric moisture cure at room temperature to form elastomers. These compositions contain a diorganopolysiloxane having terminal condensable groups, a silicon compound having at least one nitrogen atom and at least three hydrolyzable groups per molecule, a reinforcing filler and a phosphoric acid ester. These compositions have improved stability and improved flow properties. Elastomers prepared from these compositions when compared with known compositions, have lower modulus values at 100 percent elongation.