(Reuters) - Shares in Canadian life insurers Manulife (>> Manulife Financial Corp.) and Sun Life (>> Sun Life Financial Inc) surged on Thursday after the companies reported third-quarter results which beat market expectations, driven in part by growth in Asia.

Like other insurance companies, Manulife and Sun Life have been attracted to Asia as the region's burgeoning middle class looks to save and invest, enabling them to offset slower growth in their domestic markets.

Shares in Manulife, Canada's biggest life insurer, were up 8.4 percent in early afternoon trading, their highest level since last December, with shares in rival Sun Life up by 10.5 percent, their highest level since May 2008.

Manulife said net income rose to C$1.2 billion from C$495 million a year earlier, benefiting from a C$297 million gain in the quarter from its investments. The company booked a C$455 million charge in the quarter after undertaking an annual actuarial review, in line with previous guidance.

Core earnings rose 14 percent to C$996 million, or 49 Canadian cents, above the average analyst estimate of 44 Canadian cents, according to Thomson Reuters I/B/E/S. That included a 16.6 percent increase from its Asian business.

Manulife has benefited from a partnership with Singapore's DBS Group (>> DBS Group Holdings Ltd), agreed last year, in which Manulife sells its products through the lender's Asian branch network.

"In Asia you have hundreds of millions of people ... moving into the middle class," Chief Financial Officer Steve Roder said in an interview, highlighting the opportunity for further growth in mainland China, the Philippines, Indonesia and Vietnam.

"That's fueling a lot of the Asian growth. We've got a lot of good momentum in our business in Asia. Over the last three or four years we've significantly expanded our distribution and we've definitely benefited from the deal we did with DBS."

Sun Life's underlying net income jumped by 21 percent to C$639 million, or C$1.04 per share, ahead of analysts' average forecast of 93 Canadian cents per share, according to Thomson Reuters I/B/E/S. Sun Life saw net income from its Asian unit rise to C$89 million compared with C$77 million a year ago.

Chief Executive Dean Connor said in an interview that Sun Life saw potential for further expansion in Asia.

"We've gone from Asia being 8 percent of Sun Life to roughly 14 percent. Our goal is to get Asia up to 20 percent-plus. That's absolutely doable. That can all be done organically," he said.

($1 = C$1.34)

(Additional reporting by Nikhil Subba and Ismail Shakil in Bengaluru; Editing by Jeffrey Benkoe and Jonathan Oatis)

By Matt Scuffham