United said they had agreed a four-year contract with express and logistics company DHL. While the club did not give exact details, a source with knowledge of the deal said it was worth 40 million pounds.
That is more than the Old Trafford team received in the early 2000s from a shirt agreement with Vodafone although it is less than the 80 million pounds media reports have said their existing shirt deal with insurance brokerage Aon is worth.
"This deal breaks new ground in the English game," United chief executive David Gill said in a statement.
"We are delighted DHL has chosen to pioneer training kit sponsorship with the club. Their global presence and international standing are a perfect fit for the world's most popular football club."
The deal comes in a month where the club has been linked with a $1 billion Singapore stock market listing.
United have declined to comment on speculation but sources with direct knowledge of the situation have said a preliminary application has been filed and media reports have said 25 to 30 percent of the club will be sold.
United won a record 19th league title last season and their on-field success has been matched by strong commercial revenue figures.
In May, quarterly financial results showed there was a 30 percent rise in commercial revenue compared to the same period the previous year.
REVENUE GROWTH
DHL, part of Deutsche Post AG, will have their logo on training kit worn by first, reserve and youth team players during domestic competitions.
Chief spokesman Dan Johnson said the Premier League was not aware of any other English clubs having their training kit sponsored but added the national team had a similar deal for the 2006 World Cup in Germany.
In addition to the DHL contract, United also announced a three-year partnership deal with Vietnamese mobile telecoms company Beeline, the latest in a string of "territory specific" agreements that has contributed to commercial revenue growth.
Asia is an attractive market to United, with the club saying 190 million of its more than 300 million fans live on the continent - a fact analysts have pointed to as a reason why any stock market listing would make sense in Singapore.
"The [Beeline] deal will give the club's estimated 16 million fans in Vietnam a chance to see all the goals scored, as well as exclusive interviews, news and behind-the-scene access - bringing them closer to Old Trafford than ever before," United said in a news release.
