The 110th Congress opened with the passage of sweeping new rules intended to curb the influence of lobbyists by prohibiting them from treating lawmakers to meals, trips, stadium box seats or the discounted use of private jets.

But it didn't take long for lawmakers to find ways to keep having fun at the expense of corporate lobbyists.

The lobbyists and their employers typically end up paying for the events, but within the new rules.

Instead of picking up the tab directly, lobbyists pay a political fund-raising committee and, in turn, the committee pays the lawmaker's way. The prices listed are for corporate political action committees. And the lobbyists usually pay for their own travel and hotel rooms, too.

Lobbyists and fund-raisers say such trips are becoming increasingly popular, partly as a quirky consequence of the new ethics rules. By barring lobbyists from spending a couple of hours with a lawmaker or his staff for the cost of a steak dinner, the restrictions have stirred new demand for pricier tickets to social fund-raising events.

Lobbyists say the rules might even increase the volume of contributions flowing from lobbying firms to Congress.

Meredith McGehee, policy director of the Campaign Legal Center, which advocates tighter campaign finance rules, said that organizing a fund-raising trip was not the same as accepting a free vacation. But she added: "At the end of the day, it is the same thing. Members of Congress are becoming more and more creative in finding ways to engage lobbyists to help pay for their campaigns."

Some lawmakers acknowledge that fund-raising trips resemble the lobbyist- paid junkets that Congress voted overwhelmingly to prohibit. Jennifer Crider, a spokeswoman for the Democratic Congressional Campaign Committee, said its leader had decided to stop holding such overnight events for lobbyists with political action committees because of the seeming inconsistency.

So the committee canceled its annual Colorado ski weekend for lobbyists and lawmakers to raise money for the next campaign. Gone, too, is its Maryland hunting trip with John Dingell of Michigan, chairman of the House Energy and Commerce Committee.

But other congressional party campaign committees have not stopped their events, including the Democratic Senatorial Campaign Committee's annual Nantucket weekend for donors who contribute $25,000. And individual lawmakers are still playing host to plenty of events themselves.

The excursions would be illegal under the new ethics rules if lobbyists or their employers paid for them directly. (The rules have already taken effect in the House, and they are expected to take effect in the Senate this spring.)

And some outings involving personal entertainment or recreation for lawmakers could also run afoul of legal restrictions on the personal use of campaign money if they were paid for by a lawmaker's re-election campaign.

But they are allowed, and increasingly common, because of a combination of loopholes. First, the ethics rules restrict personal gifts but not political contributions, so paying to attend a fund-raiser is still legitimate. Second, the "personal use" restrictions apply to lawmakers' re-election campaigns but not to their personal political action committees, which can spend money on almost anything. Lawmakers use their personal political action committees to sponsor most of the events.

The lawmakers' so-called leadership political action committees began proliferating about a decade ago, initially as vehicles for senior members of Congress to build loyalty among their colleagues by funneling money to their campaigns.

These days, however, even the newest members of Congress usually start them. And many use them mainly to pay for travel or miscellaneous other costs. Over the last two years, the roughly 300 political action committees controlled by lawmakers raised a total of about $156 million and used only about a third of that on federal campaign contributions, according to the Center for Responsive Politics, a group that tracks political fund-raising.

Vacation-like fund-raising events with lobbyists are not new. But the new ethics rules barring lobbyists from treating lawmakers to less expensive amusements have given new importance to such getaways.

"I have to have some personal contacts to be a lobbyist," said James Dyer, a lobbyist at the firm of Clark & Weinstock. "If the only ticket in terms of contact is these fund-raising events, it is going to be costly," Dyer said. "The fund- raising part of our lives is a very expensive tool."

Thomas Susman, a lawyer who was an editor of the American Bar Association lobbying manual, said that at a recent presentation about the new rules to the lobbyists' trade group, "the biggest question was, 'Is this going to drive everything to the fund-raising side? Is that going to be the way to have social contact with members?'"

Some members of Congress said it would not bother them if the upshot of the new rules turned out to be more contributions.

"I am not going to hide from the fact that we have to raise money," said Representative Devin Nunes, a California Republican who has invited donors to his political action committee on a wine-tasting tour in June, modeled after the movie "Sideways."

"Only a moron would sell a vote for a $2,000 contribution," Nunes said.

Fund-raising consultants for both parties said they saw a golden opportunity.

"We are definitely seeing an increase in the number of events across the board," said Dana Harris of Bellwether Consulting, a Republican firm that specializes in courting corporate political action committees. "Fund-raising events will provide a safe haven for lobbyists to talk to members."