Charlie Baker has joined a bipartisan group of governors asking Congress to re-authorize the United States Export-Import Bank before its charter expires on June 30.

Associated Industries of Massachusetts, meanwhile, is dispatching its top international trade executive to Washington this week to meet with the Bay State Congressional delegation about extending the life of the 80-year-old lending institution. Kristen Rupert, Executive Director of the AIM International Business Council, is expected to tell lawmakers that Export-Import is an indispensable tool for smaller and medium-sized companies looking to expand markets overseas.

Reauthorization faces significant opposition from Congressional conservatives, who argue that the bank is putting taxpayer money at risk for a purpose better addressed by the private sector.

The Export-Import Bank helps American exporters sell abroad by offering low-cost loans, insurance and guarantees against potential losses. The bank authorized $27 billion in credit during 2013 to support an estimated $37.4 billion in U.S. export sales while returning $1.06 billion in interest and fees to the Treasury.

In Massachusetts, small businesses in industry sectors as varied as food, textiles, software, plastics, machinery, chemicals, jewelry and paper have benefitted from Export-Import Bank financing during the past few years. Bay State firms report that export growth translates directly to job growth.

Baker is among some 30 governors to sign the letter to House Speaker John A. Boehner, House Minority Leader Nancy Pelosi, Senate Majority Leader Mitch McConnell and Minority Leader Harry Reid. Former Governor Deval Patrick signed a similar letter last year.

“As governors of states whose economies and workforces depend on exports, we strongly urge you to support legislation that provides for the long-term reauthorization of the U.S. Export-Import Bank (Ex-Im Bank) before its charter expires on June 30, 2015. The Ex-Im Bank is a crucial tool that both small and large businesses use to compete fairly in the world market, increase their exports, stimulate job creation, and contribute to the growth of our states’ economies,” governors’ letter reads.

“As the official export credit agency of the United States, the Ex-Im Bank assumes the credit and country risks that private sector lenders are unable or unwilling to accept, and without it, U.S. firms would lose many sales to overseas competitors. The Ex-Im Bank allows our companies and workers to compete on a level playing field against international competitors who receive extensive support from their own export credit agencies.”

The Ex-Im Bank helped 3,413 small companies across the nation start or expand their export business last year. In the Bay State, 57 exporters, most classified as small businesses, received assistance from the bank to facilitate more than $749 million in exports.