* Drop supports view that sanctions impair even legal deals
* Overall U.S. exports to Iran increase from grain sales
* Sales of vegetables, butter and surgical instruments go up
By Arshad Mohammed
WASHINGTON, Feb 8 (Reuters) - Exports of U.S. pharmaceuticals to Iran were cut in half last year, according to data released on Friday, while overall U.S. exports to the Islamic republic rose about 9 percent because of grain sales.
The official U.S. government statistics appear to support the claims of sanctions lawyers and some independent experts that financial sanctions are making it harder for Iranians to obtain medicine despite loopholes designed to permit such trade.
The United States and its European allies have tightened their economic sanctions on Iran to pressure the government to rein in its nuclear program, which the West suspects aims to produce a bomb. Iran says the program is for peaceful purposes such as generating electricity and producing medical isotopes.
U.S. officials have said they have tried to sanction Iran without unduly harming ordinary Iranians, for example granting licenses to U.S. companies who wish to export pharmaceuticals, medical devices, food and other humanitarian goods to Iran.
However, sanctions lawyers have said the blacklisting of Iran's major banks has made it extremely difficult to find smaller Iranian banks able to conduct such licensed transactions as well as international banks willing to deal with them.
According to data released by the U.S. Commerce Department on Friday, overall U.S. exports to Iran rose to $250.2 million from $229.3 million in 2011.
However, most of the increase is attributable to the sale of wheat and other grains. These amounted to $89.2 million last year - the single largest category of U.S. exports to Iran.
In 2011, the United States exported no wheat or such grains to Iran, though it sold $21 million of maize.
Without the wheat sales, U.S. exports to Iran would have declined overall last year, sharply in some categories.
Exports of pharmaceuticals fell to $14.8 million from $31.1 million in 2011, while sales of vitamins, medicinal and botanical drugs decreased to $4.9 million from $10.8 million in 2011.
Exports of surgical appliances and supplies also declined to $2.4 million last year from $3.7 million the previous year.
Sales of pulp mill products - which include the raw material for diapers - dropped to $26.3 million from $57.9 million and exports of cattle fell to $5.3 million from $7.3 million.
However, sales of some humanitarian goods rose. Surgical and medical instrument exports rose to $7.6 million from $6.5 million and sales of dental equipment and supplies to $5 million from $1.9 million.
Exports of certain vegetables and melons increased to $18 million from $16 million, while creamery butter exports rose to $25.1 million from $11.2 million. (Editing by Warren Strobel and Doina Chiacu)