Research in Motion has become the most valuable company in Canada, surpassing longtime frontrunner Royal Bank.

RIM's market capitalization — share price multiplied by the number of shares — reached $67.351 billion by the close of trading Wednesday. Royal Bank's market cap at the end of the day was close behind, at $67.343 billion, according to figures from CBCNews.ca's market data provider.

RIM three-month TSX tradingRIM three-month TSX trading

RIM took the top spot thanks to a huge runup in its share price. So far this year, its shares have risen by almost 150 per cent, making it one of the best-performing stocks on the TSX.

The latest bounce in RIM shares came Tuesday, after Alcatel-Lucent announced it would sell RIM's BlackBerry wireless device to customers in China. Earlier this month, the Waterloo, Ont.-based company announced it had passed the 10-million-subscriber mark.

Royal Bank shares, on the other hand, have fallen about five per cent this year.

Royal Bank had held the market-cap top spot for two years, when surging energy prices after Hurricane Katrina briefly made EnCana Corp. the most valuable company in Canada.

Earlier in 2005, Manulife Financial held the top spot. It's now in third place, with a market capitalization of $62.28 billion.

Nortel Networks was the country's most valuable company during the tech boom of 1999-2000. Its shares reached $124.50 at one point in mid-2000, giving it a market capitalization of almost $400 billion, or roughly 36 per cent of the entire worth of Toronto's benchmark index at the time — the TSE 300.

Nortel is now worth less than $7 billion, as the stock has plunged to $15.77 — equivalent to just $1.58 a share after accounting for a one-for-10 consolidation.  

The most valuable companies in the United States are ExxonMobil ($566 billion US), GE ($414 billion US) and Microsoft ($291 billion US).