What is a "BEA bag"?

I read this in an Agatha Christie novel from 1965:

He certainly left here on Thursday evening carrying his BEA bag.

What is a BEA bag? Is it a brand or a specific type of bag? Googling doesn't yield very specific results.

That BEA is capitalised suggests an abbreviation, indicating a BEA bag is a bag of or from BEA.

It's not a type of bag more a branded bag; a Starbucks bag is a bag from Starbucks not a bag of the Starbucks type.

BEA can stand for British European Airways, "a British airline which existed from 1946 until 1974"¹.

The period of operation of the airline fits the year of publication of the novel. That the airline was British fits with Christie being British and that the airline was "the largest domestic airline within the United Kingdom"¹ supports the notion that Christie and the intended audience of the novel would have been aware of what BEA at the time was.

Context suggests Christie refers to a bag supplied by British Europeans Airlines, possibly sold to or offered to passengers.

¹http://en.wikipedia.org/wiki/British_European_Airways