The announcement came just days after one of four Swedish peacekeepers wounded in an explosion in Afghanistan died of his injuries.
"The joint parliamentary foreign affairs and defence commission on Tuesday backed the government's proposal to place at the disposal (of the peacekeeping force) a force of maximum 375 men for 24 months," a statement from the Swedish parliament said.
The proposal must now be endorsed by parliament in its December 7th sitting.
The planned increase in troop numbers is to cater for the Swedish force taking over responsibility for a provincial reconstruction team in Mazar-i-Sharif, in the north of the country, in which they currently serve under British command, the statement said.
There are currently 11,000 International Security Assistance Force (ISAF) soldiers from 37 countries stationed in Afghanistan.
NATO, which has been in charge of the ISAF since 2003, has agreed to plans extending the peacekeeping mission into Afghanistan's more volatile south, but concerns remain over who will provide troops amid growing security fears on the ground.
The plan to send up to 6,000 extra troops for the next phase of expansion of the ISAF was provisionally agreed last week by ambassadors at the military alliance's Brussels headquarters.
A separate US-led coalition of nearly 20,000 mostly US troops, Operation Enduring Freedom, is based mainly in the south and east, the focus of attacks by Taliban and other insurgents.
The Taliban have been waging a guerrilla-style insurgency against government troops since they were removed from power in a US-led campaign in late 2001.
Attacks linked to the insurgency have killed about 1,500 people this year, most of them militants.