Fly Levels to / from the Canaries

[CTLHC]

Can anyone one explain why the flight levels used to/from the Canaries do not conform to the usual semi-circular rules? The routing used is often down over Brest, the Bay of Biscay then over Santiago and off over the Atlantic.
Look forward to learning the reason why.

[Blockla]

They use other routes too to get there; regarding levels ATC try to accommodate the most efficient level requested depending on the integration with the North Atlantic Tracks (ie Europe to Nth America) we will give them the best available; sometimes (often) this is non 'hemispherical'. The "effective" North/South traffic to the canaries crosses all the "effective" East and West bound traffic; there are limited levels (at close to optimum) available.

[CTLHC]

Sounds perfectly reasonable..thanks