A bloc led by the centre-right GERB party of former prime minister Boyko Borissov won 26.5% of votes in Sunday's election, while a pro-Western reformist bloc led by We Continue the Change (PP) had 24.6%, according to preliminary results after nearly all votes had been counted.
"A temporary technocratic cabinet or another (sixth) snap vote remain the most likely outcomes of the election," said Andrius Tursa of the Teneo political risk consultancy.
Bulgaria's prolonged political deadlock, caused mainly by personal animosity among leaders of the two main blocs, has already forced the country to delay its target date for adopting the euro, and it has yet to approve a budget bill for 2023.
The uncertainty has also hampered Bulgaria's ability to harness EU post-pandemic recovery funds, and analysts and voters fear the messy outcome of Sunday's contest could eventually lead to yet another election being held later this year.
The nationalist Revival party, which is sympathetic to Russian President Vladimir Putin in the Ukraine war and opposes Bulgaria joining the euro, placed third in Sunday's election with 14.1%, up several percentage points from the previous vote last October.
The ethnic Turkish MRF was in fourth place with 13% and the Bulgarian Socialist Party (BSP), heir to the once powerful Communist Party, had 9%.
Bulgarian voters have grown weary of their politicians' failure to set aside their differences and cooperate on putting together a government able to tackle a cost of living crisis and root out rampant corruption.
"A government has to be formed in the end because we have been going to elections now for two years. State funds are being drained to finance these elections, yet they could have been used for entirely different purposes," Shishman Shishmanov, 30, a financial broker, said on Monday.
The PP and its ally Democratic Bulgaria (DB) accuse GERB of presiding over rampant corruption in the EU's poorest member state during their decade-long rule that ended in April 2021, something that Borissov denies.
For some voters, Borissov, a political veteran, could help restore a measure of stability in Bulgaria amid soaring inflation and geopolitical concerns spurred by the Ukraine war. But PP/DB have so far ruled out a coalition with GERB.
Both Borissov and Kiril Petkov, the 42-year-old, Harvard-educated leader of PP, want Bulgaria, a NATO member albeit with close historic and cultural ties to Russia, to maintain its pro-Ukraine stance in the war.
For most of the past two years, Bulgaria has been ruled by technocratic caretaker governments appointed by President Rumen Radev, an independent who is seen as relatively friendly towards Russia.
Teneo's Tursa said Borissov's GERB and PP/DB might back a technocratic cabinet because they accept the need for adoption of a 2023 budget, reforms required to access the post-COVID EU funds, and steps to prepare Bulgaria to join the euro.
The official final results of Sunday's election are expected by April 6 at the latest. Radev has promised to move quickly to invite the leader of whichever party has won most votes to launch coalition talks.