The move is intended to boost capacity by encouraging more rail operators to ply the routes which were due to opened up to market competition in the autumn.
"It is important that all means of transport are optimised and we have therefore taken the decision to allow more rail operators to use the network. The decision is valid from today (Thursday)," said infrastructure minister Åsa Torstensson in a government statement.
The Swedish government had announced in March last year it would end the state railway company's monopoly on passenger traffic on October 1, 2010.
"The decision covers the time from now until the new law is passed in the autumn. The two decisions are separate from each other but in practice this is a permanent measure as it will cover the entire interim period," said Henrik Hansson, a spokesperson for the infrastructure minister told The Local on Thursday.
Torstensson also referred to an ongoing "close dialogue" between the government and the aviation sector to find measures with which to offer support. According to the minister, the government is active in the EU process to develop guidelines for how member states can establish support mechanisms.
The government is prepared to review charges levied on airlines once traffic has returned to regular levels.
SJ has been unable to meet the extra demand caused by the flight chaos as much of its rolling stock has been undergoing service in April as a result of damage caused by the heavy snow falls during the winter.