* A Republican-run Senate would be more open to trade deals
* Also likely to be more encouraging of energy exports
* Ex-Im Bank reauthorization is in doubt
June 16 (Reuters) - American companies can expect progress on some critical U.S. trade initiatives if the Republican Party takes control of both houses of the U.S. Congress this November.
A Republican victory in the Senate may prevent the chamber's Democrats, backed by labor unions concerned about the impact of free trade on American jobs, from blocking trade legislation favored by both President Barack Obama and Republican leaders.
Pollsters currently see the Republicans with a reasonable chance of winning just enough seats to gain control of the Senate in mid-term elections, which would give them their first majority in both chambers since 2006. They easily control the House of Representatives.
There should be enough support from Republican lawmakers to advance trade legislation, though some Tea Party members are also wary of such deals. One area that might take a hit is future funding of the Export-Import Bank of the United States, the nation's export credit agency, as some conservatives see it providing "corporate welfare" through loans to foreign buyers of goods made by major U.S. companies.
A change in control of the Senate could smooth the way toward passage of a broad trade agreement with 11 Asia-Pacific nations and another pact with the European Union, said political strategists advising Wall Street firms. The trade deals could benefit exporters of agricultural produce, chemicals and auto parts, among other products and services.
The Republicans could also help get approvals for more exports of U.S. energy products, in abundance because of the shale oil and gas boom, to Europe and Asia.
"A unified Congress in one party could lead to a compromise" on trade, said Daniel Clifton, head of policy research at Strategas Research Partners in Washington.
The Obama Administration's desire for fast-track negotiating powers, which Democrat Senate Majority Leader Harry Reid opposes, could be granted in a Republican-controlled chamber. Fast-track authority sets objectives for U.S. trade negotiators in exchange for an up-or-down vote in Congress on trade deals, with no amendments allowed. Without this any deal Obama negotiated could be subject to amendments that could destroy it.
Many trade experts say this would aid talks on the Trans-Pacific Partnership (TPP), which is now in its fifth year of negotiations. Central to Obama's strategic shift toward Asia, the TPP would connect many countries, including the U.S. and Japan, by cutting trade barriers and harmonizing standards in a deal covering a third of global trade.
Estimates from the Peterson Institute put the potential increase in U.S. exports from the TPP at about $124 billion annually, mostly in business and financial services as well as agricultural and other products. Cracking open Japan's protected farm market is a key goal for the United States - while Japan was the fourth-largest importer of U.S. agriculture products, with $12.1 billion in sales in 2013, it is seen as having much bigger potential.
"We'd be getting (certain) U.S. agriculture products into Japan for the first time in 80 years," Clifton said.
Companies such as chicken, beef and pork producer Tyson Foods and agrochemical and genetically modified seeds company Monsanto Co have been lobbying for the TPP. Tyson is the largest U.S. exporter of beef; and Japan now imposes a 38 percent tariff on beef imports.
Still, some U.S. farmers are angry over growing signs that Japan could maintain certain barriers to imports, including beef, sugar or dairy products, as part of TPP compromises. If tariffs are not cut sufficiently, that could anger farmers, and invite Republican opposition to a deal.
Republican congressional control would also open the door to more natural gas exports to Asia and Europe. Japan is the biggest importer of liquefied natural gas, though it does not currently import from the U.S.
"My gut would be that they'd (Republicans) be more pro-energy which would probably have a positive impact on natural gas," said Gary Bradshaw, portfolio manager at Hodges Capital Management, which has more than $2 billion in assets.
Hodges owns shares in Cheniere Energy, which is currently turning its LNG import terminal in Cameron Parish, Louisiana into an export terminal. Other potential beneficiaries are Sempra Energy and Dominion Resources, that have approvals to develop export terminals at existing sites.
A Republican-controlled Senate could raise the pressure on federal agencies to approve more LNG exports, particularly to Europe so that it doesn't have to be so reliant on energy supplies from Russia, a major issue given the Ukraine crisis. But environmental reviews and the time needed to build facilities means speeding up that process would be difficult.
It may not, though, guarantee a smooth ride for companies that benefit from the Ex-Im Bank, which provides financing that helps many foreign companies make purchases from U.S. companies.
Some conservative Republican lawmakers argue it provides financial help to companies such as Boeing Co that don't need it, and that it distorts the free market. The shock defeat last week of Republican Majority Leader Eric Cantor by a Tea Party candidate in a primary strengthened that opposition.
The bank's charter will expire at the end of September, and needs to be reauthorized by Congress if funding for its loan making is to continue.
Cantor was the Republican who got it support in Congress, said Loren Smith, research analyst at Capital Alpha Partners in Washington. "It now becomes very difficult for an authorization to pass unless there's some kind of reform or scale-back."
One opponent is House Financial Services Committee Chairman Jeb Hensarling of Texas, whose committee has jurisdiction over the bank. He and others opposed the renewal in 2012, saying it benefits some companies at the cost of others. Delta Air Lines has also spoken out against it, saying it favors foreign competitors who can buy Boeing Co planes more cheaply than U.S. airlines can. Since 2007, Ex-Im financing of Boeing sales totals about $50 billion, according to bank statistics.
Boeing's shares fell more than 2 percent Wednesday, the day after Cantor's loss, and declined more than 4 percent for the week. A spokesperson for Boeing declined comment.
Smaller companies benefit from Ex-Im Bank as well, such as Atlas Air Worldwide, a Purchase, N.Y.-based aviation services company that has been New York State's top beneficiary of the bank's disbursements since 2007, at $711 million. Its shares declined 1.6 percent last week.
(Reporting By David Gaffen; additional reporting by Andrea Shalal-Esa in Washington)