* Project was due to start Q1, new date to be set in 6 weeks
* Angola to seek bids for 15 onshore oil exploration blocks
* Oil output up 4.5 pct in 2012, net profit drop not explained
LUANDA, Feb 25 (Reuters) - Angola has delayed plans to begin exporting liquefied natural gas (LNG) because of technical problems at its $10 billion plant, a senior executive at state oil firm Sonangol said on Monday.
Sonangol board member Baptista Sumbe told the company's annual briefing a new start date for the project, called Angola LNG, will be announced in six weeks once repairs have been completed.
Angola was initially expected to start exporting LNG in the first quarter of 2012, but the date was pushed back to the first quarter of this year after several delays..
"To our regret, the project has been delayed. In October, we faced another technical problem," Sumbe said.
"The repairs are being carried out now, and as soon as they are done, within five to six weeks, we will be able to announce publicly when the project can start," he added.
The 5.2 million tonnes-per-year project is led by Sonangol, which has a 22.8 percent stake and Chevron, which holds 36.4 percent. Eni (NYSE: E - news) , Total (NYSE: TOT - news) and BP (LSE: BP.L - news) each hold a stake of 13.6 percent.
Sonangol is the main player in the oil sector in Angola, Africa's second-largest oil producer after Nigeria. Besides holding stakes in all of Angola's exploration blocks, it is also the national concessionaire in charge of awarding licences.
Board member Sebastiao Martins confirmed that the company plans to hold a new bidding round for licenses to explore for oil in the pre-salt layer, this time for 15 onshore blocks in the Kwanza and Basin.
Analysts and investors believe drilling thousands of metres through blocks known as pre-salt, could match huge discoveries made off the Brazilian coast in similar rock formations.
Sonangol expects to get the go-ahead from the government to launch the bidding process this year, Martins added.
Angola offered offshore exploration rights in the pre-salt layer to seven oil majors including Total, BP and U.S. firm Cobalt in 2011.
Chief Executive Francisco Lemos Jose Maria said Angola's crude production rose 4.5 percent to 1.73 million barrels per day (mbpd) last year from 1.66 mbpd in 2011, a year marked by technical problems and maintenance at oil fields.
The CEO added that net profit in 2012 came in at $1.24 billion, but did not explain a drop from the previous year, when the company reported net profit of $3.3 billion.