President Obama is pressing his financial advantage over Mitt Romney, spending more than twice as much money in September, according to new federal disclosure documents.

Last month, Obama’s campaign spent $111 million compared with $55 million by Romney. Combined with their parties, Obama and the Democratic National Committee spent $139 million, while Romney and the Republican National Committee spent $103 million.

The president is spending heavily on television, accounting for $88 million last month or two out of three dollars spent. Republicans have been able to keep roughly even in advertising spending by relying on generous help from outside allies, including super PACs.

Romney and the RNC had the advantage in money in the bank, holding $191 million at the end of September compared with $150 million held by Obama and the DNC. More of the Democrats’ money is held with Obama’s campaign, however, giving them advantages under the arcane laws governing political spending.

With campaign funds, the candidate’s aides get more control over message and branding. Their advertising can also feature the candidate himself speaking to the camera, a critical motif for the closing arguments that both sides are now making. Independent groups and party committees, without access to the candidates, often focus on negative spots. Also, TV stations must give candidates the cheapest rates for airtime.

Obama has been able to direct more money to his campaign because of his ability to attract small donors. Over the past three months, Obama raised 50 percent of his money with the DNC through donors giving less than $200 at a time, according to an analysis of the reports. Romney’s campaign and the RNC raised only 25 percent of its money from such small donors. Only the first $2,500 from each donor can go to the candidate’s campaign, while anything over that must be directed to the party.

Both campaigns have been increasingly exploiting loopholes to tap their parties’ money. Obama spent $12 million on online advertising through his Obama Victory 2012 account with the DNC in September, while Romney spent $13.1 million in online advertising through his Romney Victory committee. Romney has also been splitting the cost of advertising with the RNC by running so-called hybrid ads, which aren’t considered specific to the presidential race because they include phrases like “Obama and his allies.”

Romney’s campaign disclosed spending $7.8 million for fundraising through VG LLC, but a campaign spokeswoman would not say who controls the firm. The Obama campaign declined to comment on its spending.

The president’s campaign spent $85,000 with mQube, a firm that allows him to collect money through cellphone text messages, which were recently approved by federal regulators.

Romney made more bonus payments to senior staff in September, part of their contracts for winning the GOP nomination, handing out $10,000 to $37,500 to 10 senior aides.