SPRINGFIELD, Ill. — Illinois' many potential 2010 election candidates began making it official Monday, with more than 500 hopefuls filing nominating petitions to get on the Feb. 2 primary election ballot.

Candidates who filed at the start of the first day of the weeklong filing period included Democratic Gov. Pat Quinn and his major in-party challenger, state Comptroller Dan Hynes.

Filers for governor on the Republican side included state senators Bill Brady and Kirk Dillard and DuPage County Board President Robert Schillerstrom. They are expected to be joined in the coming week by former GOP state party chairman Andy McKenna and former Republican state Attorney General Jim Ryan.

Illinois' open U.S. Senate seat — previously held by President Barack Obama, now being vacated by embattled outgoing Sen. Roland Burris, a Democrat — had drawn petitions from four Democrats and five Republicans by Monday afternoon, with more expected.

On the Democratic side, state Treasurer Alexi Giannoulias filed Monday, along with former Chicago inspector general David Hoffman. The Republican field includes U.S. Rep. Mark Kirk.

Candidates have until 5 p.m. Nov. 2 to file for inclusion on the Feb. 2 primary ballot.

Also up for election next year is the office of lieutenant governor, which has seen an influx of interested candidates following Quinn's ascension from lieutenant governor to governor with the January impeachment of ex-Gov. Rod Blagojevich. Seven lieutenant governor candidates had filed as of Monday afternoon, with others expected to join them.

Statewide candidates have to submit at least 5,000 signatures to qualify for the Democratic or Republican primaries. Other statewide offices on the ballot are attorney general, comptroller, secretary of state and treasurer.

Locally, three Democrats filed petitions for countywide offices in Madison County, and one Republican filed in St. Clair County.

Madison County Sheriff Bob Hertz and County Clerk Mark Von Nida are seeking re-election and Frank Miles, now the county's director of planning and development, will seek the Democratic nomination for county treasurer. Incumbent Treasurer Fred Bathon, a Democrat, announced recently that he would retire at the end of this year.

In a news release Monday, Miles promised voters an expanded customer service program and "a taxpayer education program that is second to none in the state of Illinois.''

In St. Clair County, Ed Cockrell, a Republican county board member, filed to run for county assessor, according to the clerk's office.

Illinois used to hold its spring primary in mid-March. The Legislature moved it up in 2008, with the stated purpose of helping Obama win the Democratic presidential nomination.