Maryland will seek a private company to build and operate a planned $2.2 billion light-rail Purple Line, marking the first time the state has used such financing on a public transit project.

Gov. Martin O’Malley (D) plans to make the announcement about the 16-mile transit link at an event in Bethesda on Monday. The governor also plans to highlight more than $1 billion in new funding for transportation projects in Montgomery County, administration officials said.

The package includes a $400 million state commitment for construction of the Purple Line, as well as more funding for county bus service, new intersections and other road work in one of the most congested regions in the state.

“It doesn’t solve every problem, but it helps us a lot,” said Montgomery County Executive Isiah Leggett (D), who plans to attend the event and was briefed on the package.

The event is the latest in a series launched by O’Malley after the passage this year of a major transportation funding bill that gradually raises gas taxes. The first increase of 3.5 cents per gallon took effect last month. By mid-2016, motorists can expect to pay as much as 20 cents more per gallon, according to legislative analysts.

Map of proposed Purple Line

At the events, including one in Prince George’s County last month, O’Malley has focused not on the unpopular tax increase but the promise of new jobs and economic development that come with the projects.

The biggest-ticket item to be touted Monday is the Purple Line, which would run along an east-west route inside the Beltway through Montgomery and Prince George’s counties. The plan calls for 21 stations, with service between Bethesda and New Carrollton.

Maryland officials are counting on the federal government to cover about $900 million of the project’s construction cost and will look for contributions from local governments and the private sector as well, said Erin Henson, a spokeswoman for the Department of Transportation. Construction could begin as early as 2015.

Maryland and other states increasingly are turning to public-private partnerships to create more flexibility in financing and construction of large-scale projects at a time when government resources are limited.

The Washington region’s most high-profile example is the recently opened high-occupancy toll lanes on Virginia’s section of the Capital Beltway. Two companies paid for most of the toll lanes’ nearly $2 billion in construction in exchange for toll revenue.

Maryland has not used a public-private partnership for a transit project but previously has used private companies’ investments to expand the Port of Baltimore and redevelop two travel plazas on Interstate 95.

With the Purple Line, Maryland is seeking a single private partner to design, construct, operate and maintain the project. In return, the state plans to offer annual payments throughout a 30- to 40-year contract period. Deductions would be made from the payments if the operator falls short on standards such as on-time performance, cleanliness and customer service, according to transportation officials.

Lt. Gov. Anthony G. Brown (D), who shepherded a bill through the legislature this year laying the foundation for greater use of such partnerships, said he thinks the state will use the approach more often.

“I can’t tell you what the next one is, but I’m sure there are many on the horizon,” said Brown, who has announced his candidacy for governor next year.

In addition to the $400 million in construction money, O’Malley on Monday plans to highlight a previously announced commitment of $280 million for right-of-way acquisition and final design work on the Purple Line.

Two other large outlays in the package also were previously announced: $100 million for right-of-way acquisition and design work on the Corridor Cities Transitway, a rapid bus line envisioned along Interstate 270; and $125 million for an interchange at I-270 and Watkins Mill Road.

New spending expected to be announced Monday includes:

●$85 million to increase the state’s operating subsidy of Montgomery’s Ride On bus service.

●$25 million for construction of a two-lane highway to carry state Route 97 around the town of Brookeville.

●$7 million for design work on two interchanges along U.S. 29, at Musgrove Road and Fairland Road.

●$ 3 million in design work for widening state Route 124 from Midcounty Highway to south of Airpark Road.

●$3 million for planning of possible road improvements along state routes 28 and 198 between state Route 97 and I-95.

Staff writer Katherine Shaver contributed to this report.