Responsa על פסחים 80:10

Q. Is a Jew permitted to eat bread from flour belonging to a Jew, baked solely by a Gentile, without the Jew's having even stirred the embers of the fire?
A. In France such bread is not eaten by Jews; even the sale of such bread to a Gentile is prohibited, lest the latter resell it to a Jew. The reason for this is that a Jew is permitted to eat bread baked by Gentiles from flour belonging to Gentiles, but he is not permitted to eat bread baked by a Gentile from flour belonging to a Jew.
SOURCES: Pr. 33; L. 342. Cf. Mord. A. Z. 830; Hag. Maim., Maakalot Asurot 17, 90; Agudah A. Z. 29; Sefer Haparnes 93.

Q. An oven was greased with fat-tail, and before it was reheated, bread was baked therein. Is it permissible to eat this bread?
A. This bread may not be eaten, lest perchance one eat it with milk. However, it may be sold to a Gentile, since in a Rabbinical prohibition we do not take into consideration the remote possibility that the Gentile will resell the bread to a Jew.
This Responsum is addressed to R. Tobiah.
SOURCES: Am I, 77.

Q. Is a Jew permitted to eat bread from flour belonging to a Jew, baked solely by a Gentile, without the Jew's having even stirred the embers of the fire?
A. In France such bread is not eaten by Jews; even the sale of such bread to a Gentile is prohibited, lest the latter resell it to a Jew. The reason for this is that a Jew is permitted to eat bread baked by Gentiles from flour belonging to Gentiles, but he is not permitted to eat bread baked by a Gentile from flour belonging to a Jew.
SOURCES: Pr. 33; L. 342. Cf. Mord. A. Z. 830; Hag. Maim., Maakalot Asurot 17, 90; Agudah A. Z. 29; Sefer Haparnes 93.