MONTREAL -- Aeroplan loyalty card members will not be able to directly earn miles at Esso gas stations effective June 1 as Imperial Oil Ltd. shifts its relationship to Loblaw Companies Ltd.

The loyalty card program notified members of the change to its 14-year partnership in an email.

It noted that 1.5 miles for every dollar spent will continue to be earned when using Aeroplan-affiliated credit cards for purchases at any retailer, including Esso.

Direct miles will continue to be earned at more than 75 partner brands, including Home Hardware, Toyota, Costco.ca, Avis and Marriott hotels.

Aimia, the operator of Aeroplan, said it is working on a promotion to earn more miles with existing partners and developing a strategy for how the program will change once the long-term partnership with Air Canada ends in 2020

Cheryl Kim, Aimia's vice-president corporate reputation and public affairs, said Esso is not a material contributor to Aimia's financial results and won't affect the company's financial guidance or strategy.

"The number of miles you earn on any particular transaction is pretty low so it's really not financially a big deal," she said in an interview.

Drew McReynolds of RBC Dominion Securities said Esso accounts for an undisclosed fraction of the 10 to 12 per cent gross billings from non-financial and non-Air Canada partners.

However, the minimal financial impact doesn't convey the overall effect on Aeroplan as it prepares for the departure of Air Canada.

"The optics of any accumulation partner defections between now and 2020 are negative in our view, making new Aeroplan partner announcements between now and 2020 that much more critical to stem changes in member behaviour," he wrote in a report.

Loblaw Imperial Oil announced Tuesday they have signed a deal that will allow PC Optimum members to earn points at more than 1,800 Esso gas stations starting this summer.

The company said members will earn 10 points per litre on fuel as well as 10 points per dollar on eligible convenience store purchases and car wash services at Esso stations.

Registered members may also receive targeted offers.

The PC Optimum program was launched earlier this year when Loblaw brought together the PC Plus and Shoppers Optimum programs.

The company faced some issues during the merger, with some members complaining online about troubles with the new app and points conversions.

The PC Optimum program is already available at Mobil gas stations.

On the Toronto Stock Exchange, Aimia's shares gained nearly four per cent at $1.60 in morning trading.