Pop-country star Shania Twain [ tickets ], who hasn't embarked on a major tour since more than a million fans caught her live during her 1998-99 outing, has unveiled plans to embark on a major outing that kicks off this fall.

The first batch of confirmed shows includes 18 cities in Canada and the northeastern U.S., running from late September through early December. More dates will be announced "soon," a press release said.

"I want the show to be a huge party," Twain said in a statement. "The stage will be set up in a way that puts me in the middle of my fans, which is right where I want to be. You can expect a lot of surprises."

According to Mercury Records, tickets for the Canadian dates will go on sale on Friday (8/22), while most U.S. tickets hit the market on Saturday (8/23). Tickets go on sale for Twain's Uniondale, NY, and New York City dates on Monday (8/25).

Twain continues to back her 2002 release, "Up!," which debuted at No. 1 on the Billboard 200 album chart in November and has sold more than 9 million copies worldwide to date, according to Mercury. Her previous release, 1997's "Come On Over," sold more than 34 million copies worldwide, and ranks as one of the top-selling female solo albums in history.

"Come On Over" led to much debate over whether Twain was too pop to be country, but Twain was unabashedly both on "Up!" The two-CD set includes country (the green disc) and pop (the red one) mixes of each of its 19 tracks, all of which were produced by her husband, Robert John "Mutt" Lange.

On Tuesday (8/19), NBC-TV will air "Shania Twain Up! Live in Chicago," a show that was taped on July 27 at Chicago's Grant Park.