Common shares (Tables)

3 Months Ended

Mar. 31, 2021

Summary of Common Shares

thousands of shares	As of Mar 31 2021		As of Dec 31 2020
Authorized		1,100,000		1,100,000
Common shares outstanding		734,077		734,077

Common Share Activities

	Thousands of shares			Millions of dollars
Balance as at December 31, 2019		743,902			1,375
Issued under employee share-based awards		7			-
Purchases at stated value		(9,832	)		(18	)
Balance as at December 31, 2020		734,077			1,357
Issued under employee share-based awards		-			-
Purchases at stated value		-			-
Balance as at March 31, 2021		734,077			1,357

Calculation of Basic and Diluted Earnings Per Share

The following table provides the calculation of basic and diluted earnings per common share and the dividends declared by the company on its outstanding common shares:

	Three Months               to March 31
	2021		2020
Net income (loss) per common share - basic
Net income (loss) (millions of Canadian dollars)		392		(188	)
Weighted average number of common shares outstanding (millions of shares)		734.1		738.9
Net income (loss) per common share (dollars)		0.53		(0.25	)
Net income (loss) per common share - diluted
Net income (loss) (millions of Canadian dollars)		392		(188	)
Weighted average number of common shares outstanding (millions of shares)		734.1		738.9
Effect of employee share-based awards (millions of shares) (a)		1.6		-
Weighted average number of common shares outstanding, assuming dilution (millions of shares)		735.7		738.9
Net income (loss) per common share (dollars)		0.53		(0.25	)
Dividends per common share - declared (dollars)		0.22		0.22

(a) For three months to March 31, 2020, the Net income (loss) per common share – diluted excludes the effect of 2.0 million employee share-based awards. Share-based awards have the potential to dilute basic earnings per share in the future.