White House officials and leaders of President Reagan's Advisory Commission on Social Security met for two hours yesterday to settle the few remaining issues blocking agreement on a package to save the system, but said they did not quite seal the deal and will meet again Saturday.

Commission Chairman Alan Greenspan said negotiators had reached a "general understanding" but not final agreement on a detailed package.

The group includes Greenspan, White House chief of staff James A. Baker III, Sens. Robert J. Dole (R-Kan.) and Daniel Patrick Moynihan (D-N.Y.), Rep. Barber B. Conable Jr. (R-N.Y.) and former Social Security commissioner Robert Ball. Sources said the group was very close to final approval of a compromise package.

But they said some points in question must be settled and the whole package reviewed by Reagan and House Speaker Thomas P. (Tip) O'Neill Jr. (D-Mass.).

The White House negotiators, according to sources, have decided not to put the full package before Reagan until they and commission leaders are in complete accord.

The key elements of the package under discussion would accelerate Social Security tax increases scheduled to be imposed in 1985 and 1990, make half of higher-income families' benefits subject to the federal income tax, delay this year's cost-of-living increase and bring under mandatory Social Security coverage all new and short-term federal employes.

Reportedly still at issue is whether an income-tax credit should be granted to workers paying the extra, accelerated Social Security tax.

In a related development, the president yesterday signed a bill designed to ease hardships for persons whose right to Social Security disability payments is being reexamined.