TORONTO (Reuters) - A push by US automakers to build more fuel efficient vehicles is playing to a strength of Canada's auto parts makers and positions them to pick up market share as the industry emerges from recession.

The Detroit-based automakers face a simple choice: adapt or die. Foreign-based manufacturers that specialize in smaller, greener vehicles are eating their lunch in car showrooms across the country, while US fuel and emissions standards have tightened, forcing innovation.

That's good news for Canadian companies such as Magna International Inc, Linamar Corp, and Martinrea, all of which could benefit from their expertise in areas like weight reduction and advanced powertrains, analysts said.

"They are very well positioned because their larger customers, particularly General Motors, Ford and Chrysler, have had no money to put into research and development for the last few years, so they have been relying on the auto parts makers to invest in research and development on their behalf," said Michael Willemse, an analyst at CIBC Capital Markets in Toronto.

Shares of Linamar have risen nearly sevenfold in value since March, when the survival of both GM and Chrysler was in doubt. Martinrea shares have climbed five and a half times in value over the same period and Magna's stock has doubled.

Magna is particularly active in developing green technology. The company, which has nearly $1 billion in net cash, has made investments in technologies for electric vehicles and fuel efficiency a priority.

"I would regard Magna as extremely strongly positioned because of its technical capabilities," said David Tyerman, an analyst at Genuity Capital Markets in Toronto.