The Ampang Line and Sri Petaling Line were originally known as the STAR LRT (abbreviation for Sistem Transit Aliran Ringan, which translates to Light Rail Transit System), a single train line with two branches originating from Sentul Timur station and sprawling to Ampang and Sri Petaling stations via Chan Sow Lin station.

STAR LRT was first conceived in the 1981 Transport Master Plan, when the government proposed a network of LRT lines connecting the Kuala Lumpur city centre to the surrounding areas.
An agreement was signed between the government and STAR in 1992.

The original system (27.4 km) consists of 25 stations built in two phases.
Phase one (12.4 km) consists of 14 stations (Ampang – Sultan Ismail) and a depot near Ampang station.
Phase two (15 km) consists of 11 stations (Chan Sow Lin – Bukit Jalil, and Sultan Ismail – Sentul Timur).
The two phases opened in December 1996 and July 1998.

The initial plan was for STAR to build, own and manage the STAR LRT.
However, STAR ran into financial difficulties, and had to be bailed out by the government.
So, in 2002, Prasarana took over the line, and renamed the STAR LRT to the STAR Line.
Operations of the line were subsequently transferred to Rapid KL in 2004 and the line was renamed the Ampang Line and Sri Petaling Line in 2005.
The Ampang Line assumed the branch line between Sentul Timur and Ampang stations, whereas Sri Petaling Line assumed the branch line between Sentul Timur and Sri Petaling stations.

In 2006, the government announced the Sri Petaling Line extension project.
The extension comprises 11 new stations over 17.7 kilometres of elevated track beyond the Sri Petaling station.
This extended the terminus of the Sri Petaling Line from Sri Petaling to Putra Heights.
Unlike the original line, which uses the Fixed-block signaling system, the extension uses the Communications-based train control (CBTC) signaling system.
As a result, when the first four stations and the next four stations opened on 31 October 2015 and 31 March 2016, the extension ran as a separate train service between Sri Petaling station and Bandar Puteri station.

Re-signaling had to be done on the original line, before the extension could be combined with the rest of the line.
Thales was awarded a contract on 3 September 2012 to upgrade the signaling system on the original line, and the installation of the new signaling was completed in July 2016.
The Ampang Line and Sri Petaling Line were originally known as the STAR LRT (abbreviation for Sistem Transit Aliran Ringan, which translates to Light Rail Transit System), a single train line with two branches originating from Sentul Timur station and sprawling to Ampang and Sri Petaling stations via Chan Sow Lin station.
STAR LRT was first conceived in the 1981 Transport Master Plan, when the government proposed a network of LRT lines connecting the Kuala Lumpur city centre to the surrounding areas. An agreement was signed between the government and STAR in 1992.
The original system (27.4 km) consists of 25 stations built in two phases. Phase one (12.4 km) consists of 14 stations (Ampang – Sultan Ismail) and a depot near Ampang station. Phase two (15 km) consists of 11 stations (Chan Sow Lin – Bukit Jalil, and Sultan Ismail – Sentul Timur). The two phases opened in December 1996 and July 1998.
The initial plan was for STAR to build, own and manage the STAR LRT. However, STAR ran into financial difficulties, and had to be bailed out by the government. So, in 2002, Prasarana took over the line, and renamed the STAR LRT to the STAR Line. Operations of the line were subsequently transferred to Rapid KL in 2004 and the line was renamed the Ampang Line and Sri Petaling Line in 2005. The Ampang Line assumed the branch line between Sentul Timur and Ampang stations, whereas Sri Petaling Line assumed the branch line between Sentul Timur and Sri Petaling stations.
In 2006, the government announced the Sri Petaling Line extension project. The extension comprises 11 new stations over 17.7 kilometres of elevated track beyond the Sri Petaling station. This extended the terminus of the Sri Petaling Line from Sri Petaling to Putra Heights. Unlike the original line, which uses the Fixed-block signaling system, the extension uses the Communications-based train control (CBTC) signaling system. As a result, when the first four stations and the next four stations opened on 31 October 2015 and 31 March 2016, the extension ran as a separate train service between Sri Petaling station and Bandar Puteri station.
Re-signaling had to be done on the original line, before the extension could be combined with the rest of the line. Thales was awarded a contract on 3 September 2012 to upgrade the signaling system on the original line, and the installation of the new signaling was completed in July 2016.
Ampang and Sri Petaling lines