The U.S. pork export market is improving in the wake of the H1N1 swine flu outbreak, and U.S. retailers are "rotating" back to the meat, the top executive at Smithfield Foods Inc. (SFD) said Wednesday.

Larry Pope, president and CEO of the largest U.S. pork processor, said the return of demand from mainland China remained the "wild card," but other markets were improving.

The outbreak of the H1N1 virus led to some restrictions on pork imports, though Pope reiterated that "there is no scientific evidence that this came from any pig."

"This thing's been way overblown," said Pope at an investor conference.

He said demand from Mexico - seen as the source of the outbreak - was returning quickly, while Japan, South Korea and Russia were all improving.

Smithfield is restructuring its pork business and, helped by lower feed costs, expects to improve its year-end liquidity to $1.1 billion from a previous forecast of $1 billion.

In recent trading, its shares were down 3.8% at $11.55.

-By Doug Cameron, Dow Jones Newswires; 312-750-4135; doug.cameron@dowjones.com