The Al-Nour Party, the political arm of the ultraconservative Salafi movement, won around 20 percent of the vote.
The secular and liberal forces that largely drove Egypt's uprising against former leader Hosni Mubarak were trounced, failing to turn their achievement into a victory at the polls. The secular alliance of Egyptian Bloc and youth Revolution Continues won less than 10 percent of the seats.
The results mirror those from the first round of voting, held in late November, when the two blocs together won nearly 70 percent.
A third round of voting is to be held Jan. 3-4. It is not expected to alter the result and could strengthen the Islamists' hand.
The exact numbers of seats won by each group is not immediately known because of the complicated voting system Egypt is using. Some seats are determined by a direct competition between candidates, while others are divvied out in proportion to each party's percentage of votes. The commission is to announce the actual numbers of seats at the end of the entire vote.
The commission on Saturday also suspended announcement of results for few seats because of lawsuits filed by candidates citing irregularities.
The election is the first since Mubarak's Feb. 11 ouster and is the freest in Egypt's modern history. The 498-seat People's Assembly, the parliament's lower house, will be tasked, in theory, with forming a 100-member assembly to draft a new constitution.
But its actual role remains unclear. The military council that has ruled since Mubarak's fall says the parliament will not be representative of all of Egypt, and should not have sole power over the drafting of the constitution. Last week, the military appointed a 30-member council to oversee the process.