British Airways has served Kuala Lumpur for 50 years - the routes they have flown are innummerable. BA even formed Malaysia-Singapore Airlines!
During the early 1980s, BA flew BA11 and BA9 via KUL using B747 Classics via Muscat/Bahrain/Abu Dhabi/Bombay and onwards to Singapore/Perth/Melbourne/Sydney/Auckland/Brisbane.
In 1984, BA took Kuala Lumpur off the Kangaroo route on certain days because there was sufficient traffic to operate a L1011 TriStar as BA33 via Bahrain/Abu Dhabi/Bangkok and onwards to Manila. Gradually all of BA's services to Kuala Lumpur were operated using the TriStar. This was just about the beginning of the end as the TriStars were unpopular and flight times were too long (on certain days the flights took 19 hours to reach London whilst Malaysia Airlines were flying 747s with just one-stop at Dubai in 15 hours.)
In 1989, British Airways reintroduced the 747-Classic on BA33 and passengers returned with profits. BA also introduced BA149 which operated LHR-KWI-MAA-KUL which was unfortunately caught in Kuwait at the start of the Gulf War - British Airways received much poor media publicity in the Malaysian press as passengers were negotiated out of the war-stricken city. BA suffered badly from this and passengers switched back to MAS.
The 747-400s arrived at about the same time and BA reintroduced Kuala Lumpur on to the Kangaroo route diverting BA9 via KUL on flights to Perth, Adelaide, Melbourne and Auckland. BA149 also became a one-stop service via MAA. BA stopped flying KUL-MNL at this point and began researching Indonesia as a possibility.
The reintroduction of BA9 had a positive effect as BA was beginning to compete with MAS once again but MAS was always one-step ahead and began a daily non-stop service using its own 747-400s.
During the mid-1990s, frustrated with UK-Malaysian aviation talks MAS sought help from Virgin who were keen to bash BA. MAS got the approval to double its services to London. BA Malaysia meanwhile appealed to BA London to take MAS on and compete but BA London did not listen (to be honest that is the bottom line) and on concluding its stake in Qantas decided to let QF run its Malaysian operations. QF was not keen on KUL as a destination and BA Malaysia fought back to reinstate someone from BA to run the operations. With this BA launched a weekly LHR-KUL-CGK service which was well-received and well liked by passengers.
BA33 was a huge success operating full on the LHR-KUL sector and picking up some traffic between KUL and CGK. KUL-CGK operated on average with about 100 passengers on each flight. BA London approved BA Malaysia's plans to expand and the service went up to 6x a week until the economic crisis forced BA to ditch CGK.
In 1998, BA revamped BA33 to fly LHR-KUL-SYD which again was well-liked and well-received but QF saw little profit on it code-share so a new strategy had to be conceived. BA decided to go it alone and operate a point-to-point LHR-KUL service. Disaster as the 747-400s were oversized and ripped profits from the route.
The arrival of the 777s saved the route and is BA's longest 777 service but as we see it has only just saved the route for over a year - come April - we say 'Farewell to BA' who ironically built Malaysian Aviation.