Philanthropist H.F. "Gerry" Lenfest will give $750,000 to city campaigns to increase college-graduation rates, Mayor Nutter announced Monday.

Through the foundations of Lenfest and his wife, Marguerite, $200,000 in each of the next three years will go to a mayoral initiative that provides resources through a central website - www.phillygoes2college.com - to help students plan for and finance higher education and to connect them with mentors.

An additional $150,000 will go to study the city's college-bound student population, and determine which strategies work and where students fall short in their college careers.

Upon taking office, Nutter said he wanted to double the college attainment rate from 18 percent to 36 percent by 2017 - a figure he places currently at 21 percent - and increase the high school graduation rate from 56 percent in 2009 to 80 percent by 2014.

At Monday's news conference, Lenfest said he was interested in other types of secondary education as well, such as trade schools.

"It's our pleasure to support the efforts of Mayor Nutter to ensure that all Philadelphians have access to quality information and resources to help them earn a college degree," he said.

"Gerry Lenfest, you have done it again," said Nutter, who stepped to the same lectern in City Hall in October to announce a $500,000 foundation gift from Lenfest that would pay city costs for 10 parades and festivals from 2009 through 2012.

Lori Shorr, Nutter's chief education officer, said the $150,000 study grant will allow the Mayor's College Ready Committee to analyze the performance of students who make it to college "to really get to understand that pipeline better."

Lenfest made his fortune with Suburban Cable, which he sold to Comcast Corp. in 1999. His foundation has concentrated its efforts in rural areas with low graduation rates that were served by his company. But he is increasingly turning his attention to the city, calling his latest contribution "an investment in Philadelphia's future."

Contact staff writer Jeff Shields at 215-854-4565 or jshields@phillynews.com.