While heterosexuals in Sweden can choose to marry in either a civil ceremony or a church ceremony, homosexuals are only allowed to register their partnerships in a civil ceremony. But this could all change should parliament pass legislation due to be presented shortly
"Sweden could have a gender neutral marriage law by May 1, 2009," Reinfeldt told Swedish Radio.
Civil unions granting gays and lesbians the same legal status as married couples have been allowed in Sweden since 1995.
If the new legislation is adopted, Sweden, already a pioneer in giving same-sex couples the right to adopt children, would become the first country in the world to allow gays to marry within a major church.
The Lutheran Church, which was separated from the state in 2000, has since January 2007 offered gays a religious blessing of their union. It has previously said it wants the word "marriage" reserved for heterosexual unions.
Pastors who do not want to perform a gay wedding ceremony may however have the right to refuse, something gay rights' activists have criticized.
In 2007, 74 percent of Swedes were members of the Lutheran Church.
Sweden's four-party centre-right government has been split on the issue, with the junior partner Christian Democrats also opposed to the use of the word "marriage" for homosexual unions.
However the three other parties, the conservative Moderates, the Liberals and the Centre Party, are in favour of a gender neutral law that eliminates the current reference to marriage as something between a man and a woman.
The opposition Social Democrats, the country's biggest party, also support such a law, and together the parties would garner enough support to adopt the legislation in parliament.
The issue has been a tricky one for Reinfeldt and the leader of the Christian Democrats, Göran Hägglund.
"The coalition government has agreed that we will present a basic marriage bill to parliament. The three parties in favour of a gender neutral marriage law will then present an accompanying motion seeking to have such a law in place by May 1, 2009," Reinfeldt said.
Hägglund said he was disappointed the coalition had failed to reach a compromise, telling news agency TT "there should have been a way to find a joint agreement."