Chief commercial operator Tony Camacho and UK head of marketing and sales Adam Harris are among those whose jobs are in jeopardy after being told by Ryanair that redundancies would be announced at the end of the month.
Ryanair chief executive Michael O'Leary revealed that all Buzz operations would be rebranded Ryanair in a bid to make KLM's loss-making budget offshoot profitable within 12 months.
"O'Leary told us he was looking to integrate certain departments and we've had no assurances about our jobs," said Harris.
The decision spells an end to Buzz's £5m advertising campaign, created by WCRS with media by Media Planning Group. Smith Bundy Carlson, Buzz's below-the-line agency, will also lose out.
KLM launched Buzz in January 2000 as a budget carrier 'with frills'.
The airline flies to primary airports such as Paris Charles de Gaulle rather than the cheaper secondary airports.
While these routes are likely to be kept on by Ryanair in the medium term, frills such as pre-allocated seats and cooked meals will be cut.