Transfer pricing question

Delta and Gamma are two divisions of a company. Delta manufactures two products X and Y. X is sold outside the company. Y is sold only to Division Gamma at a unit transfer price of £176. Unit costs for product Y are :
Variable materials -£60
Variable labour -£40
Variable overhead-£40
Fixed overhead-£20

Division Gamma has received an offer from another company to supply a substitute for Y for £152 per unit.
Assuming Division Delta can sell as much of product X as it can produce and the unit profitability of X and Y are equal, what will be the effect on profits if Gamma accepts the offer? Will it change, increase or decrease?