Canada's third-biggest life insurer by assets said its underlying net income fell to $573 million, or 93 cents per share, in the first quarter ended March 31, from $582 million, or 95 cents per share, a year earlier.

Underlying net income excludes the impact of interest rate and equity market movements.

Analysts on average had expected earnings of 99 Canadian cents per share, according to Thomson Reuters.

Underlying net income in the U.S slumped 28.4 per cent to $58 million, while the measure in its Canadian business, its biggest unit, jumped 5 per cent to $229 million, the company said.

The company's total life and health sales rose to $772 million from $488 million, while wealth sales stood at $37.6 billion, up from $33.2 billion.

Sun Life's total assets under management rose 7.8 per cent to $927.28 billion at the end of the quarter.

Rival Manulife Financial Corp last week reported a rise in first-quarter earnings, slightly beating market forecasts with help from strong sales in Asia.