UPDATE 1-Turkmenistan says work has started on Afghan section of gas pipeline to Pakistan, India

to Pakistan, India@

* Turkmenistan will use pipeline to supply Pakistan, India

* Pipeline had been delayed due to problem crossing Afghanistan

* Turkmenistan holds world's 4th largest natural gas reserves (Adds detail, background)

SERHETABAT, Turkmenistan, Feb 23 (Reuters) - Turkmenistan on Friday announced the start of construction work on the Afghan section of an $8 billion natural gas pipeline that will link the energy-rich Central Asian nation to Pakistan and India.

Ex-Soviet Turkmenistan holds the world's fourth-largest natural gas reserves but has been heavily dependent on gas exports to China after Russia cut back gas imports in the past few years.

"Galkynysh, the world's second-biggest gas field, will feed the TAPI (Turkmenistan-Afghanistan-Pakistan-India) pipeline," Turkmen President Kurbanguly Berdymukhamedov told reporters gathered in a town near the Turkmen-Afghan border through a video link.

Berdymukhamedov was in the western Afghan city of Herat together with Afghan President Ashraf Ghani, Pakistani Prime Minister Shahid Khaqan Abbasi and India's Minister of State for External Affairs M.J. Akbar.

The TAPI project, supported by the United States and the Asian Development Bank, has been touted by Turkmenistan since the 1990s. But starting work on the pipeline has been delayed because of the problem of crossing Afghanistan.

The pipeline will allow Turkmenistan to find new consumers in Asia and cut its dependence on Beijing, which buys about 35 billion cubic metres (bcm) of gas annually. (Reporting by Marat Gurt; Writing by Olzhas Auyezov; Editing by Christian Schmollinger and Joseph Radford)