The aid package, which will be approved “shortly”, will be geared towards the tourism sector, restaurants, bars and other small businesses, Sánchez told parliament.
“It's a significant amount of resources to continue supporting… sectors that were growing and competitive before the pandemic, but which now are logically facing a very difficult situation,” he said.
The aim is to “bolster the balance sheets”, the premier said without giving further details.
The tourism sector and other industries hard hit by the pandemic have for months asked the government for direct aid, but Sánchez's administration has until now rejected that option, offering state-backed loans as well as access to the furlough scheme.
It has so far unblocked €116 billion in credit lines since the start of the pandemic and another €40 billion to provide furloughed workers with 70 percent of their basic salary and to help the self-employed.
Last summer, the government also set up a €10-billion fund to bail out firms in “strategic sectors” that are considered viable but experiencing solvency problems.
Spain's economy contracted sharply by 11 percent in 2020, one of the worst performers in the eurozone, with its key tourism sector battered by the pandemic.
The number of registered jobless in Spain jumped by nearly 23 percent last year to nearly 3.9 million, according to labour ministry figures.
The country's public debt stockpile stood at €1.3 trillion at the end of December, up 10 percent from December 2019 as public expenditure increased and income shrank.