GENEVA — The Grand Canyon, Mount Everest and Loch Ness will vie with more than 200 other spectacular places in the next phase of the global competition for the New 7 Wonders of Nature, organizers said Wednesday.

The 261 nominees from 222 countries include some of the most famous mountain peaks, lakes and other attractions, such as the Great Barrier Reef and Niagara Falls.

Over a billion people are expected to join in Internet voting that will nominate 77 semifinalists for the top natural wonders, which will share in the glory already enjoyed by the seven man-made wonders chosen 18 months ago.

“We are calling on people all over the world to actively show their appreciation for our … natural world by joining together to celebrate the most extraordinary sites on our planet,” said Tia Viering, spokeswoman of the New 7 Wonders campaign.

The Swiss-based nonprofit foundation collected 441 nominations over the Internet since it opened the selection process in 2007.

The foundation then chose the top vote-getter from each country, making a list of 222 sites. The overall list rose to 261 with the inclusion of sites shared by two or more countries — such as Niagara Falls and Lake Superior between Canada and the United States, and the Matterhorn, between Switzerland and Italy.

Votes can be cast until July 7. Registration on the Web site aims to prevent people from voting twice.

The quarterfinalists include some lesser known sites, such as Yasur Volcano on the south Pacific island of Vanuatu or Nigeria’s Zuma Rock, a giant monolith in the middle of the African country.

A panel of experts in nature, chaired by Federico Mayor, former chief of UNESCO, the U.N. Educational, Scientific and Cultural Organization, will reduce the list to 21 finalists in July.

The seven winners will then be chosen in another round of public voting lasting until 2011, this time by Internet, telephone and text messages.

Around 100 million people voted in the selection of the seven man-made wonders. The winners were the Colosseum, Italy; the Great Wall of China; the Taj Mahal, India; Petra, Jordan; Christ the Redeemer Statue, Brazil; Machu Picchu, Peru; and the Pyramid at Chichen Itza, Mexico.

“The enthusiasm for the campaign, which brought culture out of dusty corners and back to life on front pages, TV screens and computers everywhere, crossed all social and economic lines,” said Viering. “Everyone from schoolchildren to entrepreneurs eagerly participated.”

Choosing world wonders has been a continuing fascination over the centuries. UNESCO keeps updating its list of World Heritage Sites, which now totals 878 places.

The New 7 Wonders campaign led by Swiss adventurer Bernard Weber aims to promote cultural diversity by supporting, preserving and restoring monuments and natural sites. It relies on private donations and revenue from selling broadcasting rights.

See the list

The full list of nominees is at www.new7wonders.com