"This bill won't do much of anything for us," he said.
But in 2010, when Melgen first invested in GFS, the firm was actively considering marketing its natural gas engine devices for on-road vehicles. The bill, both in its 2009 and 2012 versions, authorized changes to IRS rules allowing larger tax credits for on-road, natural gas-supplied trucks and vehicles as well as grants for research. The proposal also urged the Environmental Protection Agency to streamline rules covering the conversion of diesel and gas engines to natural gas and alternative fuels.
GFS said in October 2010 in a press release that its strategy "integrates four related areas of business development," including "on-road coal truck conversions." The release, written by the company's consultant and then-director of strategic projects, Elio Muller, also said that "a vast number of on-road 18-wheeler tractor-trailer trucks hauling coal" in the Appalachian region of Kentucky and West Virginia could be converted to combination diesel-natural gas engines with the GFS system.
Muller, a former Commerce Department official in the Clinton administration involved in several Tampa businesses, said last week that he introduced Melgen to Green and other GFS officials in early 2010. Green also said Muller was instrumental in bringing the company to Melgen's attention. Muller said he has known Melgen from Florida's Democratic political circles dating back to the late 1990s. At one point, Muller drew up plans to start a business, Melgen & Muller Inc., but the men never followed through.
Melgen has made investments in health-related companies since the 1990s, according to SEC reports, but his GFS stake is his only evident natural gas-related investment. Green said he met several times with Melgen and found him to be an "intelligent investor" but could not explain his sudden interest in natural gas.
"I don't know how he found out about natural gas, but he liked what we were doing and thought it was innovative," Green said.
By early 2010, when Melgen formally joined GFS, Menendez had already taken on a key role in backing the natural gas bill, joining Democratic Senate Majority Leader Harry Reid of Nevada and Republican Sen. Orrin Hatch of Utah as out-front sponsors.
The NAT GAS Act quickly drew energy and environmental battle lines. Oil and alternative energy magnate T. Boone Pickens led corporate natural gas industry backers of the bill, aided by the Obama administration and influential environmental groups. Arrayed against the bill were top oil and coal firms and even some green activists, joined by industrialists David and Charles Koch, whose political action group, Americans for Prosperity, harnessed opposition from conservative groups.
Green said he did not authorize or hire any lobbyists on behalf of GFS because he was skeptical about broadening into the markets for on-road trucks. But he did not block the activities of Muller, who in addition to his consulting role with GFS, had also started his own firm, Diesel 2 Gas. It aimed to license GFS technology and use the firm's parts to outfit on-road trucks.
In June 2010, representing both GFS and Diesel 2 Gas, Muller testified before an EPA panel in Ann Arbor, Mich., about what he called "cumbersome and unnecessary" rules that hurt GFS and other natural gas firms. The EPA agreed to alter its regulations in April 2011.
Between 2009 and 2011, Muller also ran an independent consulting firm, Muller Group Inc., which paid $220,000 to lobbyists from Brownstein Hyatt Farber Schreck LLP to lobby for the NAT GAS Act and related issues.
Muller said he accompanied the lobbyists in at least one meeting with Menendez' staff about the bill but could not recall details. Melgen and Muller joined Menendez at a signing ceremony in Miami in January 2010 for the senator's book, "Growing American Roots." And last June, they joined Menendez at the annual U.S.-Spain Council Annual Forum in Jersey City.
Muller said he did not discuss his lobbying activities with Melgen, even though they were both involved with GFS.
Both Muller and Melgen also have fundraising ties to Menendez. Muller gave $5,000 to Menendez' New Jersey Senate re-election campaign in 2011. Melgen has been a staunch supporter, giving more than $14,000 directly to Menendez since the late 1990s and, through his eye clinic, donating $700,000 last year to a "super" political committee that supported Democratic Senate candidates. The committee, in turn, spent $582,000 to back Menendez' campaign.
AP Writers Erica Werner in Washington and Ezequiel Abiu Lopez in Santo Domingo contributed to this report.