Jailed U.S. Man Likely Focus of Carter Cuba Trip

* Carter to discuss ways to improve U.S.-Cuba relations

* Only ex U.S. president to visit Cuba since revolution

* Could serve as intermediary between the governments

By Jeff Franks

HAVANA (Reuters) - Former U.S. President Jimmy Carter will begin a three-day visit to Cuba Monday for what is described as a "private, non-governmental mission" where the main topic may be the fate of a U.S. aid contractor jailed for setting up illegal Internet service.

The timing, coming shortly after contractor Alan Gross was sentenced to 15 years in a Cuban prison, and Carter's past as an unofficial diplomatic troubleshooter suggest he will intervene on Gross's behalf, although no one has said so publicly.

The Carter Center said Cuba invited him down to "learn about new economic policies and the upcoming (Communist) Party congress and to discuss ways to improve U.S.-Cuba relations."

Gross is a major stumbling block for the longtime ideological enemies because the United States has said relations, which warmed modestly before his arrest, are on hold until he is free.

After arrival with wife Rosalynn, Carter's first public event will be with Havana's Jewish community, supposedly the recipient of Gross's help in setting up Internet service under a U.S.-funded program outlawed in Cuba.

Then he will see Cuban Catholic leader Cardinal Jaime Ortega, whose talks with President Raul Castro last year resulted in the release of most of the island's political prisoners.

On Tuesday, Carter, 86, will converse with Castro, 79, before a Wednesday press conference and his departure.

Castro is in the midst of preparing for a Communist Party congress in April where reforms to Cuba's Soviet-style economy are expected to be approved.

Neither Gross nor former leader Fidel Castro were on the schedule issued by the Cuban government, but Carter seems likely to meet with them and perhaps Cuban dissidents as well.

He has played a mediating role in other international problems, including last August when he went to North Korea to secure the release of an American imprisoned there.

RESPECTED BY THE CASTROS

There has been no indication he is coming to Cuba at the behest of U.S. President Barack Obama, so it is not clear what he can offer the Cubans, but he is respected by the Castros.

In a 2002 visit he called for an end to the longstanding U.S. trade embargo against the island, but also said Cuba needed democracy and better human rights, and gave dissidents a boost by publicly mentioning their movement.

While in the White House, he took steps such as lifting a general ban on U.S. travel to Cuba and remains the only U.S. president, in or out of office, to visit the island since the 1959 revolution that turned it into a communist state.

What Carter could do, said John McAuliff of the New York-based Fund for Reconciliation and Development, is act as an intermediary between the U.S. and Cuban governments.

"Hopefully, Carter can close the gap, not only by facilitating a humanitarian resolution of the Alan Gross case, but also by encouraging a positive response from Washington," said McAuliff, who advocates improved U.S.-Cuba relations.

Obama has eased U.S. travel restrictions to Cuba and restarted talks on migration and postal issues, but McAuliff said more steps, such as removing the island from the list of terrorist-sponsoring countries, are needed.

Gross, 61, was in Cuba working under a U.S. program promoting political change on the island, which Cuba views as subversive.

A Cuban court this month found he committed "acts against the independence and territorial integrity of the state" and gave him a 15-year sentence.

The U.S. has said he was in Cuba only to provide Internet access to Jewish groups and committed no crime. It has demanded his release, which many think Cuba is willing to do because it made its point about displeasure with the U.S. pro-democracy programs and because of humanitarian concerns.

Gross's 26-year-old daughter and 88-year-old mother have been diagnosed with cancer since his arrest in December 2009.

Wife Judy Gross said on Saturday the family was "desperate for his return home." (Reporting by Jeff Franks, editing by Anthony Boadle)