MONTREAL - Aimia Inc. (AIM.TO) says it will buy back 22.9 per cent of its outstanding shares at a price of $4.30 each under a plan announced last month.

The loyalty rewards company says it will buy back roughly 34.9 million shares, reducing its issued and outstanding shares to about 117.4 million.

Aimia said last month it would spend up to $150 million to buy back stock under a "modified Dutch auction."

By buying back its shares, a company spreads its profits over fewer shares. That increases its return on equity and earnings per share, two key ratios used to determine a company's financial health.

The company says shares tendered to the offer but not repurchased will be returned to shareholders.

Aimia sold its Aeroplan loyalty program earlier this year to Air Canada.