(CNN) -- How do you dispose of Syria's chemical weapons stockpiles? Call in private industry.
The Organization for the Prohibition of Chemical Weapons announced Friday it has invited chemical disposal firms to let the group know if they're interested, but added that it's working on a tight schedule.
The request for "expressions of interest" comes a week after the organization's executive council asked its director-general to explore "options for destruction in chemical disposal facilities" of chemicals that Syria has declared.
The document lists 19 chemicals. Most of Syria's declared chemical weapons program includes common industrial chemicals or otherwise chemicals that can safely be rendered harmless or destroyed, the OPCW said.
An estimated 1.8 million pounds (800 metric tons), accounting for a major part of Syria's stockpile, is to be disposed of commercially at a cost estimated at $47 million to $54 million, it added.
The companies will also destroy the effluent resulting from the "effective destruction" of higher-priority chemicals.
But hurry. The closing date for receipt of an expression of interest is November 29.
A joint OPCW-United Nations team charged with overseeing the destruction of the weapons began inspecting sites in October. The U.N. Security Council resolution that authorized the mission set a deadline of mid-2014 for Syria to destroy its chemical weapons or face consequences.
The OPCW said it expected that "the most critical chemicals" would be removed from Syria by the end of 2013.
The U.N. resolution on Syria's chemical weapons was based on a deal struck between the United States and Russia that averted an American military strike over allegations the Syrian government used sarin nerve gas in an August 21 attack on a Damascus suburb. U.S. officials said at least 1,400 people died in the attack. Syria denied responsibility, blaming rebel forces.
In an update last Friday, the OPCW said it had verified that more than 60% of Syria's declared unfilled munitions had been destroyed. Syria has committed to destroy all unfilled warheads and bombs by January 31.
It follows its announcement on October 31 that Syria had destroyed all its declared chemical weapons mixing, filling and production facilities and that all of the chemical weapons at inspected sites were under seal.
Opposition factions unite
The movement on the chemical weapons front came as six opposition fighting factions announced Friday the formation of a new alliance: the Islamic Front.
"This blessed front has been formed with the will of God to fulfill our countrymen's ambitions in Syria and in accordance with their aspirations and to pave the way for the gradual unification of factions and founding movements," Ahmed Issa Alsheikh, an official of the group, said in a video statement on Al Jazeera Arabic.
The alliance includes tens of thousands of fighters from some of Syria's most powerful Islamist groups, including Ahrar al-Sham, Suqour al-Sham, the Islamic Army and the Tawhid Brigade. The groups control territory in key areas across Syria and have been fighting forces loyal to President Bashar al-Assad along the critical lines of Damascus and Aleppo, among others.
"The Islamic Front will be militarily, politically, and socially independent and its aim will be the complete fall of the Assad regime and the creation of a sovereign Islamic state," Abu Firas, a spokesman for the Tawhid Brigade, the largest rebel faction in Aleppo, said in an online statement.
The announcement diminishes the stature of the Western-backed Free Syrian Army and its leadership abroad, the Syrian National Coalition, as leaders inside the country seek to distance themselves from a command structure criticized for failing to serve the opposition's needs on the ground.
"This will change and it will increase our numbers and unify our ideology," said Capt. Islam Alloush, a spokesman for the Islamic Army, an alliance member, in an interview with CNN. "We are optimistic that this will make us stronger."
The moves come after the al Qaeda-linked Islamic State of Iraq and the Levant succeeded as the predominant military force in northern Syria, marginalizing and even fighting Syria's more moderate factions.
ISIS's largely foreign fighting force poses a threat to cash-strapped rebel groups competing for funding, resources and influence in Syria's more than two-year civil war.
The Syrian conflict began in March 2011 after government forces cracked down on peaceful protesters during the Arab Spring movement and is now a full-blown civil war. The United Nations estimates that more than 100,000 people have died in the conflict.
CNN's Susannah Cullinane contributed to this report.