State television announced the unanimous approval of about 300 economic proposals in a full session of the Party Congress, but it did not give details. Newscast presenters said the party's new leadership has also been decided, without naming names.
More details are expected Tuesday when the summit closes with a speech by Raul Castro. While the Party Congress does not have the power to enact the changes into law, the suggestions are expected to be acted upon quickly by the National Assembly over the coming days and weeks.
Officials called the gathering to set a new course for Cuba's economy and rejuvenate an aging political class largely made up of octogenarians who led Cuba's 1959 revolution.
Earlier Monday, an official photograph shot inside the spacious convention hall where the party confab was taking place showed Castro placing his vote inside a ballot box. "Candidacy for Members of the Central Committee," it read. A box that said "Vote for All" was checked on the ballot, indicating that Castro had approved an entire slate of candidates, though their names were not visible.
Fidel and Raul Castro have held the top two spots in the Communist Party since its creation in 1965. But at this year's Sixth Party Congress, there is an air of mystery surrounding the leadership vote.
In March, Fidel, 84, announced he had resigned as first secretary of the party when he ceded the presidency to Raul several years ago, although the party's website still lists him as its leader.
In a speech opening the Congress this weekend, Raul warned that a new generation is needed to take over when the old guard is gone.
He even proposed term limits for officials including the president - a taboo subject during the half-century in which Cuba has been ruled by either him or his brother. The goal is to create opportunities for younger politicians to get experience, Raul said.
The speech intensified speculation the job might go to someone such as Lazaro Exposito, the young Communist Party chief in Santiago de Cuba, or Marino Murillo, the former Economy Minister who has been put in charge of implementing the economic reforms.
With change in the air, officials have repeatedly emphasized a message of continuity amid transition, and Fidel Castro echoed that theme in an essay published earlier Monday.
"The new generation is being called upon to rectify and change without hesitation all that should be rectified and changed," Castro wrote.
"Persisting in revolutionary principles is, in my judgment, the principal legacy we can leave them," he said.
Divided into five committees and meeting behind closed doors, party delegates considered more than 300 proposals for economic changes, many of which were first announced last year. They affect sectors from agriculture and energy to transport and taxation, and let many Cubans go into business for themselves in private ventures.
Nevertheless officials have stressed that the changes are meant to "update" Cuba's economic model. State TV repeated Monday night that their objective is to "guarantee the continuity of socialism in Cuba."
The newscast announcing the approval of the measures followed a two-hour special program in which viewers saw delegates from around the country discuss the fine points of a document that has not yet been made public.
One long-demanded measure apparently approved would recommend legalizing the buying and selling of private real estate by Cuban nationals. Islanders have been clamoring for years to end restrictions on such sales.
Other measures cover providing credit to independent workers who need capital to launch their businesses and eliminating the island's unique dual-currency system, under which workers are paid in Cuban pesos, while many imported goods are available only in a dollar-linked currency that is beyond most people's reach.
The ration book is one of the most cherished of subsidies on the island, but Raul Castro has repeatedly said it is unsustainable, and a disincentive to work.
Associated Press writers Andrea Rodriguez and Paul Haven contributed to this report.