Santa Rosa formally agreed this week to host the start of the 2012 Tour of California, a proposition that will be three times more costly for the community but promises a bigger economic boost.

After hosting a stage of the tour for five years from 2006 to 2010, the tour is skipping Santa Rosa entirely in 2011. But the nation's premiere cycling event will come back in a big way in 2012, agreeing to let the race begin in Santa Rosa.

"This is a whole new race for us and brings with it a whole new set of responsibilities," said Raissa de la Rosa, a program specialist with the city's economic development department.

Instead of a stage event that lasts a day and a half, the tour start is a far more involved affair. Riders and tour organizers begin arriving eight days before the race, increasing the number of hotel nights and meals needed for the event.

There will also be galas and international press conferences and other downtown events leading up to the May 13 race start.

"This is a tremendous opportunity for our community," Mayor Ernesto Olivares said.

The City Council unanimously authorized City Manager Kathy Millison to sign the agreement with tour owner AEG Sports. The deal calls for the city to commit to spending $580,000 on the event, far more than the $190,000 cost of hosting a stage.

The higher cost is expected to be borne largely by fund-raising and corporate sponsorships. The city already has pledges for 40 percent of the requirement: a $120,000 commitment from Bike Monkey publishing and special events company and from Santa Rosa professional cyclist Levi Leipheimer's King Ridge GranFondo cycling event. The city's Business Improvement Area has also pledged $100,000 to the event.

The city expects to raise the balance from corporate sponsors, de la Rosa said.

Because of the increased length of time that teams, event organizers and visitors will be spending in the city, de la Rosa estimated the economic impacts of the race start at $6.8 million, including the creation of nearly 70 jobs and the generation of $81,500 in taxes.

Leipheimer, who attended the council meeting, has given the city "incredibly valuable" guidance for securing the right to host the start, de la Rosa said.

The route for the race has not been determined.