The surface area of a sphere is given by the formula A = 4πr^2, where r is the radius of the sphere. 

The diameter of the sphere is equal to 2r. 

If the surface area of the sphere increased by 44%, then the new surface area is 1.44A. 

Substituting the formula for the surface area into this expression, we get 1.44A = 1.44(4πr^2) = 4π(1.2r)^2. 

This shows that the new radius of the sphere is 1.2r, which means that the radius increased by 20%. 

Since the diameter is equal to 2r, it also increased by 20%. 

Therefore, the percentage increase in diameter is 20%