"To me it looks like they're trying to capitalize on a situation where a company is a bit down and out because of the impact of launching a lot of initiatives that have yet to pay off, as well as the fallout from the pilot situation a year ago", he said.
Since 1996, along with WestJet's regional airline, WestJet Encore, the airline offers service to more than 100 destinations in North America, Central America, the Caribbean and Europe and to more than 175 destinations in over 20 countries through their airline partnerships.
This isn't Onex's first attempt to acquire an airline. Air Canada shares rose more than 5%.
The deal was announced before markets opened on Monday.
The price represents about a 67 per cent premium to the shares, which closed Friday at $18.52 - roughly the same price it reached the year of its initial public offering.
Analysts said the Onex bid is rich by airline standards, representing a premium to the valuations given to Air Canada and publicly traded US airlines.
WestJet will then function as a privately-held company.
WestJet's stock price is down by 17 per cent in the past 12 months amid rising fuel costs and soft revenues.
"Privatizing tends to be easier to generate value longer term", said Chan.
In February, WestJet announced plans to scale back capacity growth to cut costs and attract higher-paying customers to turn it around after a hard 2018.
The investment will be led by Onex Partners, Onex's private equity platform focused on larger investment opportunities and WestJet's board has urged shareholders to vote in favor of the deal.
"Onex' aerospace experience, history of positive employee relations and long-term orientation makes it an ideal partner for WestJetters, and I am excited about our future,"Clive Beddoe, WestJet's founder and chairman, said in the statement".
Alberta's Premier said on Monday that WestJet and Onex have assured him the carrier's headquarters will remain in Calgary after the deal.
Tawfiq Popatia, a managing director at Onex, said WestJet is among Canada's strongest brands.
"Other workers at WestJet are able to sit down at the table and negotiate with the company when changes are made because they are unionized", Scanlan said.
"WestJet frontline workers across Canada have been signing Unifor cards, showing that they want to have a voice in the company", said Unifor National President Jerry Dias.
These include gaining court approval as well as gaining official government approval under the Canada Transportation Act.
"We do not believe this transaction dramatically alters the competitive landscape, at least negatively", Canaccord Genuity analyst Doug Taylor said.